Marco Zanetti

A reliability study was conducted.To develop a classification system for lumbar disc degeneration based on routine magnetic resonance imaging, to investigate the applicability of a simple algorithm, and to assess the reliability of this classification system.A standardized nomenclature in the assessment of disc abnormalities is a prerequisite for a comparison of data from different investigations. The reliability of the assessment has a crucial influence on the validity of the data. Grading systems of disc degeneration based on state of the art magnetic resonance imaging and corresponding reproducibility studies currently are sparse.A grading system for lumbar disc degeneration was developed on the basis of the literature. An algorithm to assess the grading was developed and optimized by reviewing lumbar magnetic resonance examinations. The reliability of the algorithm in depicting intervertebral disc alterations was tested on the magnetic resonance images of 300 lumbar intervertebral discs in 60 patients (33 men and 27 women) with a mean age of 40 years (range, 10-83 years). All scans were analyzed independently by three observers. Intra- and interobserver reliabilities were assessed by calculating kappa statistics.There were 14 Grade I, 82 Grade II, 72 Grade III, 68 Grade IV, and 64 Grade V discs. The kappa coefficients for intra- and interobserver agreement were substantial to excellent: intraobserver (kappa range, 0.84-0.90) and interobserver (kappa range, 0.69-0.81). Complete agreement was obtained, on the average, in 83.8% of all the discs. A difference of one grade occurred in 15.9% and a difference of two or more grades in 1.3% of all the cases.Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation.

Forty-one patients scheduled for shoulder surgery underwent computed tomography (CT) and magnetic resonance imaging (MRI) examination of their affected shoulder to verify whether fatty degeneration of the rotator cuff muscles could reproducibly be assessed by CT or by MRI and whether the grading with the 2 methods was comparable. In addition, rotator cuff muscle cross-sectional areas were measured on parasagittal MRI scans to establish a possible correlation between rotator cuff muscle atrophy and fatty degeneration. Interobserver reproducibility for grading fatty degeneration was good to excellent for CT and for MRI. The correlation between MRI and CT was fair to moderate and remained unsatisfactory, even if the classification system was simplified with only a 3- rather than a 5-grade scale as originally proposed. The degree of fatty degeneration was significantly related to the amount of atrophy of the respective muscles.

PURPOSE: To correlate magnetic resonance (MR) images of a bone marrow edema pattern with histologic findings in osteoarthritic knees. MATERIALS AND METHODS: Sixteen consecutive patients (age range, 43–79 years; mean, 67 years) referred for total knee replacement were examined with sagittal short inversion time inversion-recovery (STIR) and T1- and T2-weighted turbo spin-echo MR imaging 1–4 days before surgery. Tibial plateau abnormalities on MR images were compared quantitatively with those on histologic maps. RESULTS: The bone marrow edema pattern zone (ill-defined and hyperintense on STIR images and hypointense on T1-weighted MR images) mainly consisted of normal tissue (53% of the area was fatty marrow, 16% was intact trabeculae, and 2% was blood vessels) and a smaller proportion of several abnormalities (bone marrow necrosis [11% of area], abnormal [necrotic or remodeled] trabeculae [8%], bone marrow fibrosis [4%], bone marrow edema [4%], and bone marrow bleeding [2%]). The bone marrow edema pattern zone and the zone with a normal MR imaging appearance differed significantly in the presence of bone marrow necrosis (P = .021), bone marrow fibrosis (P = .014), and abnormal trabeculae (P = .011) but not in the prevalence of bone marrow edema (P = .069). Bone marrow edema also was found in zones with an unremarkable MR appearance (perifocal zone, 5% edema; control zone, 2% edema). CONCLUSION: A bone marrow edema pattern in osteoarthritic knees represents a number of noncharacteristic histologic abnormalities. Edema is not a major constituent of MR imaging signal intensity abnormalities in such knees.

To retrospectively characterize magnetic resonance (MR) arthrographic findings in patients with cam femoroacetabular impingement (FAI) and in those with pincer FAI.Institutional review board approval and informed consent were not required. MR arthrographic studies obtained in 50 consecutive patients (30 men, 20 women; mean age, 28.8 years) with FAI were analyzed for labral abnormalities, cartilage lesions, and osseous abnormalities of the acetabular rim. The nonspherical shape of the femoral head at the head-neck junction was measured in eight positions around the femoral head and neck and used to calculate the alpha angle. Acetabular depth was measured. Surgical diagnosis served as the reference standard. The Wilcoxon rank sum test was used for statistical analysis.At surgery, hips in 33 patients were classified as having cam FAI and hips in 17 patients were classified as having pincer FAI. In both groups, the mean age of patients was 28.8 years. There were significantly more men (n = 27) with cam FAI and more women (n = 14) with pincer FAI. The alpha angle was significantly larger in patients with cam FAI at the anterior and anterosuperior positions. The acetabulum was significantly deeper in patients with pincer FAI than in patients with cam FAI. Cartilage lesions at the anterosuperior and superior positions were significantly larger in patients with cam FAI than in patients with pincer FAI. Cartilage lesions at the posteroinferior position were significantly larger and labral lesions at the posterior and posteroinferior positions were more pronounced in patients with pincer FAI than in patients with cam FAI. Osseous abnormalities were not significantly different between the groups. Osseous bump formation at the femoral neck was significantly more common in patients with cam FAI than in patients with pincer FAI.Characteristic MR arthrographic findings of cam FAI include large alpha angles and cartilage lesions at the anterosuperior position and osseous bump formation at the femoral neck; characteristic findings of pincer FAI include a deep acetabulum and posteroinferior cartilage lesions.

CT scan is the gold standard for the measurement of the tibial tuberosity-trochlear groove distance (TTTG). The aim of this study was to evaluate the reliability of the TTTG on MRI compared to CT scan. Twelve knees in 11 patients underwent CT and MRI examination for patellofemoral instability or anterior knee pain. Both the bony and the cartilaginous landmarks of the trochlear groove were used for the measurement of the TTTG. The measurements were performed by two experienced musculoskeletal radiologists. The interrater, intermethod and interperiod reliability was calculated using a restricted maximum likelihood estimation and a Bland-Altman analysis. The mean TTTG referenced on bony landmarks was 14.4+/-5.4 mm on CT scans, and 13.9+/-4.5 mm on MR images. The mean TTTG referenced on cartilaginous landmarks was 15.3+/-4.1 mm on CT scans, and 13.5+/-4.6 mm on MR images. An excellent interrater (82%), intermethods (86%), and interperiod (91%) quantitative reliability was found. TTTG can be determined reliably on MRI using either cartilage or bony landmarks. Additional CT scans are not necessary.

To identify the magnetic resonance (MR) abnormalities of the lumbar spine that have a low prevalence in asymptomatic patients and thus determine the findings that are predictive of low back pain in symptomatic patients.Sagittal T1-weighted and sagittal and axial T2-weighted MR images were obtained in 60 asymptomatic volunteers aged 20-50 years. The MR images were evaluated with regard to intervertebral disk abnormalities, end plate abnormalities, and osteoarthritis of the facet joints by two musculoskeletal radiologists independently.Disk bulging or disk protrusion was found in 42 (14%) and 48 (16%) of the intervertebral spaces in 37 (62%) and 40 (67%) subjects, respectively. High-signal-intensity zones were found commonly (in 23 [7.7%] and 25 [8.3%] of the intervertebral spaces in 19 (32%) and 20 (33%) subjects, respectively). Disk extrusions were less common (in 11 [3.7%] and 11 [3.7%] of the intervertebral spaces in 11 (18%) and 11 (18%) subjects, respectively). There were no disk sequestrations. A nerve root compression in a single intervertebral space was diagnosed by one reader. End plate abnormalities were found in two (0.7%) and six (1.9%) of the intervertebral spaces in two (3%) and six (10%) subjects, respectively. No severe osteoarthritis was diagnosed by either reader.In patients younger than 50 years, disk extrusion and sequestration, nerve root compression, end plate abnormalities, and osteoarthritis of the facet joints are rare and, therefore, may be predictive of low back pain in symptomatic patients.

The purpose of this study was to establish a magnetic resonance (MR) imaging standard for quantification of the muscles of the rotator cuff.Parasagittal T1-weighted turbo spin-echo images of the shoulder were obtained in 70 asymptomatic subjects (35 women, 35 men; age range: 21-70 years, mean: 45 years). Standardized cross-sectional areas (rotator cuff muscle areas divided by the area of the supraspinatus fossa) and standardized signal intensities (related to signal intensities of the teres major muscle) were measured and compared with 30 patients with different stages of rotator cuff tears and 10 patients with glenohumeral instability. In addition, a so-called tangent sign was evaluated with the hypothesis that a healthy supraspinatus muscle crosses a line (tangent) drawn through the superior borders of the scapular spine and the superior margin of the coracoid.Cross-sectional areas of the muscles of the rotator cuff were variable in asymptomatic subjects. Cross-sectional areas (but not signal intensities) did discriminate patients with different stages of rotator cuff tears from asymptomatic subjects. The tangent sign was negative in all asymptomatic subjects but positive in four and nine of 10 patients with medium and large rotator cuff tears, respectively.A method for quantification of the muscles of the rotator cuff using MR imaging is presented. Cross-sectional areas can be used for quantification of the muscles of the rotator cuff. The tangent sign is a useful MR sign for atrophy of the supraspinatus muscle.

A bstract The discovery by the ATLAS and CMS experiments of a new boson with mass around 125 GeV and with measured properties compatible with those of a Standard-Model Higgs boson, coupled with the absence of discoveries of phenomena beyond the Standard Model at the TeV scale, has triggered interest in ideas for future Higgs factories. A new circular e + e − collider hosted in a 80 to 100 km tunnel, TLEP, is among the most attractive solutions proposed so far. It has a clean experimental environment, produces high luminosity for top-quark, Higgs boson, W and Z studies, accommodates multiple detectors, and can reach energies up to the $$ \mathrm{t}\overline{\mathrm{t}} $$ threshold and beyond. It will enable measurements of the Higgs boson properties and of Electroweak Symmetry-Breaking (EWSB) parameters with unequalled precision, offering exploration of physics beyond the Standard Model in the multi-TeV range. Moreover, being the natural precursor of the VHE-LHC, a 100 TeV hadron machine in the same tunnel, it builds up a long-term vision for particle physics. Altogether, the combination of TLEP and the VHE-LHC offers, for a great cost effectiveness, the best precision and the best search reach of all options presently on the market. This paper presents a first appraisal of the salient features of the TLEP physics potential, to serve as a baseline for a more extensive design study.

This Conceptual Design Report describes LUXE (Laser Und XFEL Experiment), an experimental campaign that aims to combine the high-quality and high-energy electron beam of the European XFEL with a powerful laser to explore the uncharted terrain of quantum electrodynamics characterised by both high energy and high intensity. We will reach this hitherto inaccessible regime of quantum physics by analysing high-energy electron-photon and photon-photon interactions in the extreme environment provided by an intense laser focus. The physics background and its relevance are presented in the science case which in turn leads to, and justifies, the ensuing plan for all aspects of the experiment: Our choice of experimental parameters allows (i) effective field strengths to be probed at and beyond the Schwinger limit and (ii) a precision to be achieved that permits a detailed comparison of the measured data with calculations. In addition, the high photon flux predicted will enable a sensitive search for new physics beyond the Standard Model. The initial phase of the experiment will employ an existing 40 TW laser, whereas the second phase will utilise an upgraded laser power of 350 TW. All expectations regarding the performance of the experimental set-up as well as the expected physics results are based on detailed numerical simulations throughout.

To investigate the predictive value of magnetic resonance (MR) imaging of abnormalities of the lumbar intervertebral disks, particularly with adjacent endplate changes, to predict symptomatic disk derangement, with discography as the standard.Fifty patients aged 28-50 years with chronic low back pain and without radicular leg pain underwent prospective clinical examination and sagittal T1- and T2-weighted and transverse T2-weighted MR imaging. Subsequently, patients underwent lumbar discography with a pain provocation test (116 disks). MR images were evaluated for disk degeneration, a high-signal-intensity zone, and endplate abnormalities. Results of pain provocation at discography were rated independently of the image findings as concordant or as nonconcordant or painless. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to assess the clinical relevance of MR abnormalities.Normal disks on MR images were generally not painful at provocative discography (NPV, 98%). Disk degeneration (sensitivity, 98%; specificity, 59%; PPV, 63%) and a high-signal-intensity zone (sensitivity, 27%; specificity, 85%; PPV, 56%) were not helpful in the identification of symptomatic disk derangement. When only moderate and severe type I and type II endplate abnormalities were considered abnormal, all injected disks caused concordant pain with provocation (sensitivity, 38%; specificity, 100%; PPV, 100%).Moderate and severe endplate abnormalities appear be useful in the prediction of painful disk derangement in patients with symptomatic low back pain.

To establish quantitative and qualitative magnetic resonance (MR) criteria for the diagnosis of trochlear dysplasia.MR images were analyzed in 16 consecutive patients with and 23 without trochlear dysplasia. The standard of reference was a true lateral radiograph of the knee. Quantitative and qualitative MR criteria were assessed.In patients with trochlear dysplasia, the trochlear groove was significantly less deep than that in control subjects. The most accurate measurement was 3 cm above the femorotibial joint space (P: <.001), where a trochlear depth of 3 mm or less had a sensitivity of 100% and a specificity of 96%. The ventral trochlear prominence between the supratrochlear femoral cortex and the most ventral point of the trochlear floor (midsagittal section) was always larger than 6.9 mm in dysplastic trochleae. A facet ratio of less than 2:5 (medial to lateral) 3 cm above joint space level had a sensitivity of 100% and a specificity of 96%. A nipplelike anterior prominence at the superior end of the femoral trochlea on midsagittal images was a specific (91%) qualitative criterion.Dysplasia of the femoral trochlea can be diagnosed reliably by using quantitative or qualitative criteria on midsagittal or transverse MR images obtained 3 cm above the femorotibial joint space.

PURPOSE: To evaluate the diagnostic performance of magnetic resonance (MR) arthrography in the detection of articular cartilage lesions in patients suspected of having femoroacetabular impingement and/or labral abnormalities. MATERIALS AND METHODS: Forty-two MR arthrograms obtained in 40 patients with a clinical diagnosis of femoroacetabular impingement and/or labral defect were retrospectively analyzed. Two readers independently interpreted the images for cartilage lesion location, depiction, and characteristics. Within 6 months after MR arthrography, each patient underwent open hip surgery, during which the entire cartilage of the hip joint was inspected. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. κ values were calculated to quantify the level of interobserver agreement. RESULTS: At surgery, most (37 [88%] of 42) cartilage defects were identified in the anterosuperior part of the acetabulum. In 23 (55%), 12 (29%), 10 (24%), and 10 (24%) hips, lesions were found in the posterosuperior acetabulum, anteroinferior acetabulum, posteroinferior acetabulum, and femoral head, respectively. The sensitivities and specificities of MR arthrographic detection of cartilage damage in all regions combined were 79% (73 of 92 regions) and 77% (91 of 118 regions), respectively, for reader 1 and 50% (46 of 92 regions) and 84% (99 of 118 regions), respectively, for reader 2. At interobserver comparison, agreement was fair (κ = 0.31) for detection of cartilage lesions in the femoral head and poor (κ ≤ 0.2) for detection of lesions in all acetabular regions. CONCLUSION: Cartilage lesions are common in young and middle-aged patients with femoroacetabular impingement and/or labral abnormalities and are most frequently found in the anterosuperior part of the acetabulum. © RSNA, 2003

To evaluate the magnetic resonance (MR) arthrographic findings in patients with frozen shoulder.Preoperative MR arthrograms of 22 patients (six women, 16 men; mean age, 54.7 years) with frozen shoulder treated with arthroscopic capsulotomy were compared with arthrograms of 22 age- and sex-matched control subjects without frozen shoulder. The thickness of the coracohumeral ligament (CHL) and the joint capsule, as well as the volume of the axillary recess, were measured (Mann-Whitney test). Abnormalities in the CHL, subcoracoid fat, superior glenohumeral ligament, superior border of the subscapularis tendon, long biceps tendon, and subscapularis recess were analyzed in consensus by two blinded radiologists (chi(2) test).Patients with frozen shoulder had a significantly thickened CHL (4.1 mm vs 2.7 mm in controls) and a thickened joint capsule in the rotator cuff interval (7.1 mm vs 4.5 mm; P < .001 for both comparisons, Mann-Whitney test) but not in the axillary recess. The volume of the axillary recess was significantly smaller in patients with frozen shoulder than in control subjects (P = .03, Mann-Whitney test). Thickening of the CHL to 4 mm or more had a specificity of 95% and a sensitivity of 59% for diagnosis of frozen shoulder. Thickening of the capsule in the rotator cuff interval to 7 mm or more had a specificity of 86% and a sensitivity of 64%. Synovitis-like abnormalities at the superior border of the subscapularis tendon were significantly more common in patients with frozen shoulder than in control subjects (P = .014, chi(2) test). Complete obliteration of the fat triangle between the CHL and the coracoid process (subcoracoid triangle sign) was specific (100%) but not sensitive (32%).Thickening of the CHL and the joint capsule in the rotator cuff interval, as well as the subcoracoid triangle sign, are characteristic MR arthrographic findings in frozen shoulder.

To prospectively evaluate magnetic resonance (MR) imaging findings of abductor tendons and muscles in asymptomatic and symptomatic patients after lateral transgluteal total hip arthroplasty (THA).The institutional review board approved the study, and all patients provided informed consent. Two musculoskeletal radiologists blinded to clinical information analyzed triplanar MR images of the greater trochanter obtained in 25 patients without and 39 patients with trochanteric pain and abductor weakness after THA. Tendon defects, diameter, signal intensity, and ossification; fatty atrophy; and bursal fluid collections were assessed. In 14 symptomatic patients, MR imaging and surgical findings were correlated. Differences in the frequencies of findings between the two groups were tested for significance by using chi2 analysis.Tendon defects were uncommon in asymptomatic patients and significantly more frequent in symptomatic patients: Two asymptomatic versus 22 symptomatic patients had gluteus minimus defects (P < .001); four asymptomatic versus 24 symptomatic patients, lateral gluteus medius defects (P < .001); and no asymptomatic versus seven symptomatic patients, posterior gluteus medius defects (P = .025). In both patient groups, tendon signal intensity changes were frequent, with the exception of those in the posterior gluteus medius tendon, which demonstrated these changes more frequently in symptomatic patients (in 23 vs five asymptomatic patients, P = .002). Tendon diameter changes were frequent in both groups but significantly (P = .001 to P = .009) more frequent in symptomatic patients (all tendon parts). Fatty atrophy was evident in the anterior two-thirds of the gluteus minimus muscle in both groups, without significant differences. In the posterosuperior third of the gluteus minimus muscle, however, differences in fatty atrophy between the two groups were significant (P = .026). Fatty atrophy of the gluteus medius muscle was present in symptomatic patients only, with significant differences among all muscle parts. Bursal fluid collections were more frequent in symptomatic patients (n = 24) than in asymptomatic patients (n = 8, P = .021). The MR imaging-based diagnosis was confirmed in all 14 patients who underwent revision surgery.Abductor tendon defects and fatty atrophy of the gluteus medius muscle and the posterior part of the gluteus minimus muscle are uncommon in asymptomatic patients after THA.

The purpose of this study was to evaluate the association between rotator cuff abnormalities and reduced acromiohumeral distance.Acromiohumeral distance was measured on conventional radiographs and on MR images. Three age- and sex-matched patient groups each including 21 patients were stratified according to acromiohumeral distance on conventional radiographs (group 1, <or= 7 mm; group 2, 8-10 mm; group 3, > 10 mm). Acromiohumeral distance was related to the presence, location, and size of a rotator cuff tear and the degree of fatty degeneration of the muscle assessed on MR arthrography. The relative influence on acromiohumeral distance of the various MR arthrographic findings was assessed. Spearman's rank correlation and stepwise regression were used for statistical analysis.In group 1 (acromiohumeral distance <or= 7 mm) full-thickness supraspinatus tendon tears were present in 90% (19/21) of the patients, infraspinatus tendon tears in 67% (14/21) of the patients, and subscapularis tendon tears in 43% (9/21) of the patients. The size of rotator cuff tendon tears and the degree of fatty degeneration in all rotator cuff muscles showed a significant negative correlation with acromiohumeral distance (p < 0.05). After stepwise regression, a significant relative influence on acromiohumeral distance remained for size of rotator cuff tear (p < 0.0001) and for degree of fatty degeneration of the infraspinatus muscle (p = 0.013).Tendon tears and fatty muscle degeneration in the rotator cuff correlate with reduced acromiohumeral distance. Size of rotator cuff tear and degree of fatty degeneration of the infraspinatus muscle have the most pronounced influence on acromiohumeral distance.

To evaluate the clinical relevance of neovascularization diagnosed with power Doppler ultrasonography (US) in Achilles tendons in patients with chronic achillodynia.Forty consecutive patients (mean age, 52 years; age range, 30-72 years) were examined. US was performed bilaterally and repeated after 3 months. Shape and echogenicity were assessed with gray-scale US and vascularization with power Doppler US. All patients were treated conservatively. Clinical assessment was performed after 0, 3, and 6 months by using visual analogue scale (VAS) scores (0, no pain; 100, unbearable pain). The VAS scores were compared with the initial US findings, and analysis of variance was used for repeated measurements.Neovascularization was present in 30 of 55 painful tendons and in one of 25 asymptomatic tendons. The mean VAS scores at 0, 3, and 6 months, respectively, for tendons with neovascularization were 52, 26, and 20; those for tendons without neovascularization were 39, 19, and 18 (P =.15). Forty-eight painful and nine asymptomatic tendons were spindle shaped. The mean VAS scores at 0, 3, and 6 months, respectively, for the spindle-shaped tendons were 48, 25, and 20; those for normally shaped tendons were 33, 10, and 16 (P =.17). Thirty-five painful and four asymptomatic tendons were inhomogeneous. The mean VAS scores at 0, 3, and 6 months, respectively, for symptomatic inhomogeneous tendons were 54, 29, and 25; those for symptomatic homogeneous tendons were 32, 12, and 9 (P <.001).Although neovascularization is a specific sign for pain, it does not indicate an unfavorable outcome. Conversely, tendon inhomogeneity seems to be associated with an unfavorable outcome.

To assess diagnostic accuracy in the detection and grading of subscapularis tendon lesions at magnetic resonance (MR) arthrography.MR arthrograms in 50 consecutive patients (29 with normal subscapularis tendons, 11 with a lesion in the cranial quarter, seven with a major tear but not complete detachment, three with complete detachment) with arthroscopic or surgical confirmation were evaluated independently by two radiologists. Diagnosis was established on findings from transverse and/or parasagittal images.With transverse images alone, sensitivity was 95%/100% (reader 1/reader 2); specificity was 55%/62%. With parasagittal images alone, sensitivity was 91%/91%; specificity was 76%/90%. With combined images, sensitivity was 91%/91%; specificity was 86%/79%. Interobserver agreement was substantial (kappa = 0.67). Forty-one of 50 (82%) grades for subscapularis abnormalities matched at MR imaging and surgery; nine mismatches differed by only one degree. Several signs were specific (90%-100%) but insensitive (29%-62%); these included leakage of contrast material onto the lesser tuberosity, fatty degeneration of the subscapularis muscle, and abnormality in the course of the long biceps tendon (luxation, subluxation).MR arthrography is accurate in the detection and grading of subscapularis tendon lesions. Specificity of findings on transverse images for this diagnosis can be improved by including indirect signs and findings on parasagittal images.

A longitudinal magnetic resonance imaging investigation of lumbar disc degeneration in asymptomatic individuals was conducted.To investigate risk factors for the development or deterioration of lumbar disc degeneration.Numerous studies have explored the significance of certain risk factors for the development or progression of disc degeneration, but no comprehensive longitudinal magnetic resonance imaging-based study has been reported that simultaneously considers clinical, morphologic, physical, psychosocial, and occupational risk factors.In the 5-year follow-up evaluation of 41 asymptomatic individuals, the risk factors for the development of lumbar disc degeneration and its progression were investigated. All 41 individuals had a magnetic resonance imaging scan at baseline and at the minimum 5-year follow-up assessment using the same scanner and protocol. The magnetic resonance images were analyzed independently by two radiologists with regard to disc degeneration. Various predictor variables were assessed both at baseline and follow-up, with special emphasis on physical job characteristics, sports activities, and magnetic resonance image-based morphologic findings.Of the 41 individuals, 17 (41%) exhibited a deterioration of the disc status. In 10 individuals, the progression of disc degeneration was one grade or more. Only a weak correlation existed between progressive disc degeneration and low back pain development during a 5-year follow-up period. Multiple logistic regression analysis demonstrated that the extent of disc herniation (odds ratio [OR], 12.63; confidence interval [CI], 1.24-128.49), the lack of sports activities (OR, 2.71; CI, 1.04-7.07), and night shift work (OR, 23.01; CI, 1.26-421.31) were significant predictors for disc degeneration during follow-up evaluation when control was used for the number of degenerated discs at baseline, gender, age, and body mass index.The results indicate that the extent of disc herniation, the lack of sports activities, and night shift work are significant risk factors for the development of lumbar disc degeneration and its progression.

A system for grading lumbar nerve root compromise (no compromise, contact of disk material with nerve root, deviation of nerve root, and compression of nerve root) was tested in the interpretation of routine magnetic resonance images of 500 lumbar nerve roots in 250 symptomatic patients. Intra- and interobserver reliability was assessed for three independent observers. In the 94 nerve roots evaluated at surgery, surgical grading was correlated with image-based grading. kappa statistics indicated substantial agreement between different readings by the same observer and between different observers (for intraobserver agreement, kappa = 0.72-0.77; for interobserver agreement, kappa = 0.62-0.67). Correlation of image-based grading with surgical grading was high (r = 0.86). The image-based grading system enabled reliable evaluation and reporting of nerve root compromise.

Prospective study on individuals with asymptomatic lumbar disc abnormalities detected in magnetic resonance imaging.To determine the natural history of asymptomatic disc abnormalities in magnetic resonance imaging and to identify predictors of future low back pain-related medical consultation and work incapacity.The natural history of individuals with asymptomatic disc herniations has not been well established, but the high rate of lumbar disc alterations recently detected in asymptomatic individuals by magnetic resonance imaging demands reconsideration of a pathomorphology-based explanation of low back pain and sciatica.Forty-six asymptomatic individuals who had a high rate of disc herniations (73%) were observed for an average of 5 years (range, 54-72 months). Four classes of variables (medical data including magnetic resonance imaging-identified disc abnormalities, general psychological factors, physical job characteristics, and psychosocial aspects of work) were assessed at baseline and follow-up.Disc herniations and neural compromise did not significantly worsen at follow-up, whereas disc degeneration progressed in 17 individuals (41.5%). Minor episodes of low back pain occurred in 19 individuals (41.3%), 6 of whom had to seek medical treatment and 5 of whom had to stop work temporarily. The requirement for low back pain-related medical consultation was predicted with high accuracy by listlessness, job satisfaction, and working in shifts (P < 0.001). Work incapacity was best predicted by physical job characteristics, job disaffection, and working in shifts (P < 0.01).Physical job characteristics and psychological aspects of work were more powerful than magnetic resonance imaging-identified disc abnormalities in predicting the need for low back pain-related medical consultation and the resultant work incapacity. However,the conclusions are still preliminary, and replication of the findings in larger and more representative study samples is needed.

To compare measurements of the sagittal diameter of the lumbar dural sac obtained at positional magnetic resonance (MR) imaging and at functional myelography and to assess the influence of various body positions on the dural sac and the intervertebral foramina.Thirty consecutive patients referred for lumbar myelography were examined with an open 0.5-T MR imager, Sagittal T2-weighted fast spin-echo images were acquired with patients in the supine, upright flexion, and upright extension positions. The midsagittal diameter of the dural sac was measured at the level of the disks on MR images and myelograms. Foraminal sizes on the MR images were scored independently by two observers.Correlation between MR imaging and myelographic measurements was high (r = .81-.97). A small but statistically significant positional dependence of the dural sac diameter was found in the lower lumbar spine. Position-dependent differences in foraminal scores were uncommon.Quantitative assessment of sagittal dural sac diameters is comparable between lumbar myelography and positional MR imaging. In a selected patient population, only small changes in the sagittal diameter of the dural sac and foraminal size can be expected between various body positions, and the information gained in addition to that from standard MR imaging is limited [corrected].

To prospectively evaluate the signal intensity (SI), course, and diameter of elbow nerves and to identify anatomic variants that are potentially associated with nerve compression syndromes on magnetic resonance (MR) images of asymptomatic elbows.This study was approved by the institutional review board. Informed consent was obtained from each volunteer. Sixty subjects with asymptomatic elbows (age range, 22.4-51.7 years; median age, 32.8 years) underwent MR imaging. Increased SI compared with surrounding muscles on fluid-sensitive MR images, anatomic course, anatomic nerve and muscle variants potentially associated with nerve compression syndromes, and qualitative changes in nerve diameters were evaluated. Quantitative data on the shortest and longest nerve diameters were obtained.Increased SI on fluid-sensitive MR images was seen in the ulnar nerve in 60% (36 of 60) of subjects but was never observed in the median and radial nerves. An atypical intermuscular course of the median nerve between the brachialis and pronator muscles was detected in 17% (10 of 60) of subjects. Ulnar nerve subluxation at the level of the cubital tunnel was seen in 2% (one of 60) of subjects; an anconeus epitrochlearis muscle, in 23% (14 of 60); and a hypertrophic leash of Henry, in 15% (nine of 60). Median nerve dimensions were 2.4 x 4.0 mm (range, 1.0-4.0 x 3.0-7.0 mm) for the ulnar nerve, 1.0 x 1.9 mm (range, 0.8-2.0 x 0.9-5.0 mm) for the radial nerve, and 3.0 x 5.4 mm (range, 1.0-5.0 x 3.0-9.0 mm) for the median nerve.Increased SI of the ulnar nerve on fluid-sensitive images (60%), an atypical intermuscular course of the median nerve (17%), and an anconeus epitrochlearis muscle (23%) are common MR findings in asymptomatic elbows.

To compare the diagnostic efficacy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) with that of conventional radiography and three-phase bone scintigraphy in patients suspected of having infection in their total hip replacements.Thirty-five patients with painful total hip replacements and possible septic prosthetic loosening were examined with FDG PET, conventional radiography, and three-phase bone scintigraphy. PET, radiographic, and scintigraphic images were each evaluated by two independent observers in a blinded fashion. For 32 of 35 patients, serial conventional radiographs were available. Results of microbiologic examinations of surgical specimens represented the standard of reference in 26 patients, and results of joint aspiration plus clinical follow-up of at least 6 months represented the standard of reference in the remaining nine patients. Sensitivity, specificity, accuracy, and interobserver variability (kappa) values were calculated. The imaging modalities were compared in terms of diagnostic confidence by using the sign test.Nine patients had septic and 21 patients had aseptic loosening. In five patients, neither loosening nor infection was confirmed. For diagnosing infection with FDG PET, conventional radiography, and bone scintigraphy, respectively, sensitivity values for reader 1 and reader 2 were 33% and 22%, 89% and 78%, and 56% and 44%, while specificity values were 81% and 85%, 50% and 65%, and 88% and 92% and accuracy values were 69% for both readers, 60% and 69%, and 80% for both readers. PET was significantly more specific (P =.035) but less sensitive (P =.016) than conventional radiography for the diagnosis of infection.In a study population of patients suspected of having infected total hip replacements, FDG PET performed similarly to three-phase bone scintigraphy. FDG PET was more specific but less sensitive than conventional radiography for the diagnosis of infection.

The objective of our study was to evaluate the usefulness of FDG positron emission tomography (PET) for the differentiation of degenerative and infectious endplate abnormalities in the lumbar spine that were detected on MR imaging.FDG PET was performed prospectively in 30 consecutive patients with substantial endplate abnormalities (craniocaudal diameter of bone marrow abnormalities, > or = 25% of vertebral height) found during MR imaging of the lumbar spine. Both the MR and PET images were evaluated by two experienced musculoskeletal radiologists and two experienced nuclear physicians. The diagnosis of either degeneration with different types of endplate abnormalities or disk-space infection was determined. Clinical follow-up and, in selected cases, bone biopsies with cultures were used as the standard of reference.On the MR images, 25 of the 38 degenerated levels were classified as Modic type I, 13 levels as type II, and none as type III. Five disk-space infections were diagnosed in four patients. MR imaging findings were false-positive at one disk level with type I abnormalities and false-negative at two levels with infection. PET did not show FDG uptake in the intervertebral spaces of any patient with degenerative disease. FDG PET findings were true-positive in all five levels with disk-space infection. The sensitivity and specificity for MR imaging in detecting disk-space infection were 50% and 96%, and were 100% and 100% for FDG PET, respectively (not significant, McNemar test, p = 0.5).Our findings suggest that FDG PET may prove useful for differentiation of degenerative and infectious endplate abnormalities detected on MR imaging. Even in active (Modic type I) degenerative endplate abnormalities in our series, PET did not show increased FDG uptake.

The purpose of this study was to evaluate the prevalence of MR abnormalities of the knee on the symptomatic and contralateral asymptomatic sides in patients with suspected meniscal tears. SUBJECTS AND METHODS. One hundred patients (mean age, 42.7 years; range, 18-73 years) referred for suspected meniscal tears were prospectively examined with MRI of both knees when the contralateral knee was asymptomatic. The prevalence of various types of meniscal tears and other MR abnormalities was determined.Meniscal tears were found in 57 symptomatic knees and in 36 contralateral asymptomatic knees. In those 57 patients with a meniscal tear on the symptomatic side, the prevalence of asymptomatic tears in the contralateral side was 63% (36/57). Horizontal or oblique meniscal tears were found medially in 32 and laterally in 11 symptomatic knees, and medially in 29 and laterally in eight asymptomatic knees. Radial, vertical, complex, or displaced tears were found medially in 18 and laterally in five symptomatic knees, and medially in five and laterally in none of the asymptomatic knees. Collateral ligament abnormalities were found in 53 symptomatic knees and in six asymptomatic knees. Pericapsular soft-tissue abnormalities were found in 64 symptomatic and in 12 asymptomatic knees. Edema-like bone marrow abnormalities were found in 36 symptomatic and in three asymptomatic knees.Horizontal or oblique meniscal tears are frequently encountered in both asymptomatic and symptomatic knees and may not always be related to symptoms. However, radial, vertical, complex, or displaced meniscal tears and abnormalities of the collateral ligaments, pericapsular soft tissues, and bone marrow are found almost exclusively on the symptomatic side and appear to be clinically more meaningful.

To retrospectively assess the frequency and performance of magnetic resonance (MR) arthrography to help diagnose acetabular cartilage delamination in femoroacetabular impingement (FAI).Institutional review board approval and informed consent were waived for this retrospective study. Forty-four consecutive patients with FAI of the cam type were included (mean age, 30.7 years; range, 16-49 years), including 30 men (mean age, 30.5 years; range, 16-49 years) and 14 women (mean age, 31.4 years; range, 18-48 years). The inclusion criteria were no previous surgery, surgery within 3 months after MR imaging, and availability of a detailed surgical report with acetabular cartilage findings. MR arthrographic findings were assessed independently by two blinded readers. Findings at surgery served as reference standard. Sensitivity, specificity, accuracy, and kappa statistics for interobserver agreement were calculated.At surgery, acetabular cartilage delamination was seen in 23 (52%) of 44 patients (mean size of cartilage flap from acetabular rim, 7.6 mm; range, 2-30 mm). At MR, patients with fluid signal intensity under the cartilage delamination had a respective sensitivity, specificity, and accuracy of 22%, 95%, and 57% for reader 1 and 30%, 95%, and 61% for reader 2. A hypointense line in the acetabular cartilage on sagittal three-dimensional double-echo steady-state images with water excitation demonstrated moderate diagnostic performance (respective sensitivity, specificity, and accuracy were 70%, 57%, and 64% for reader 1 and 70%, 62%, and 66% for reader 2). Hypointense areas in the acetabular cartilage were quite specific on both coronal intermediate-weighted fat-saturated images (respective sensitivity, specificity, and accuracy were 52%, 90%, and 70% for reader 1 and 74%, 90%, and 82% for reader 2) and coronal T1-weighted images (respective sensitivity, specificity, and accuracy were 35%, 90%, and 61% for reader 1 and 61%, 95%, and 77% for reader 2).Cartilage delamination is common in patients undergoing surgery for FAI. Fluid under the cartilage delamination is a specific but rare finding. Hypointense areas in the acetabular cartilage seen on intermediate-weighted fat-saturated or T1-weighted images appear to be helpful diagnostic criteria.

Hip MRI: How Useful Is Intraarticular Contrast Material for Evaluating Surgically Proven Lesions of the Labrum and Articular Cartilage?Reto Sutter1,2, Veronika Zubler1,2, Adrienne Hoffmann1,2, Nadja Mamisch-Saupe1,2, Claudio Dora2,3, Fabian Kalberer2,3, Marco Zanetti1,2, Juerg Hodler1,2 and Christian W. A. Pfirrmann1,2Audio Available | Share Claim CREDIT

Abstract We discuss a method that employs a multilayer perceptron to detect deviations from a reference model in large multivariate datasets. Our data analysis strategy does not rely on any prior assumption on the nature of the deviation. It is designed to be sensitive to small discrepancies that arise in datasets dominated by the reference model. The main conceptual building blocks were introduced in D’Agnolo and Wulzer (Phys Rev D 99 (1), 015014. 10.1103/PhysRevD.99.015014 . arXiv:1806.02350 [hep-ph], 2019). Here we make decisive progress in the algorithm implementation and we demonstrate its applicability to problems in high energy physics. We show that the method is sensitive to putative new physics signals in di-muon final states at the LHC. We also compare our performances on toy problems with the ones of alternative methods proposed in the literature.

PURPOSE: To relate different types of radiographic contrast material distributions to anatomic compartments by using cadaveric specimens and to relate the injection site to treatment-induced discomfort and therapeutic effect. MATERIALS AND METHODS: The contrast material distributions of selective nerve root blocks (SNRBs) in 36 patients (13 women, 23 men; mean age, 52 years; age range, 22–88 years) were graded by two radiologists in conference as type 1 (tubular appearance), type 2 (nerve root visible as filling defect), or type 3 (nerve root not visible). These patterns were correlated with pain reduction after 15 minutes and 2 weeks (with a visual analogue scale of 100-mm length). In addition, 30 nerve roots were injected with iodine-containing contrast material and blue dye in three cadaveric specimens. Radiographs were compared with anatomic sections. RESULTS: After 15 minutes and 2 weeks, 75% and 86% of the patients, respectively, reported pain relief. Mean pain relief length after 15 minutes for type 1 distribution was 60 mm; for type 2, 44 mm; and for type 3, 22 mm; and after 2 weeks, it was 34 mm for type 1, 31 mm for type 2, and 57 mm for type 3. There was no correlation between early and late response. Pain during intervention was less pronounced in type 2 injection, compared with type 1 (P = .002). On the basis of anatomic sections, type 1 injection was intraepineural; type 2, extraepineural; and type 3, paraneural. CONCLUSION: Therapeutic SNRB is effective in sciatica, but early response does not predict the effect after 2 weeks. Type 1 injections are more painful than type 2 injections.

To determine the prevalence and size of presumed Morton neuromas and fluid in the intermetatarsal bursae on magnetic resonance (MR) images.In 70 asymptomatic subjects, transaxial T1-weighted spin-echo and T2-weighted turbo spin-echo images were obtained of the right forefoot. The prevalence and size of presumed Morton neuromas (diagnosed with MR imaging criteria) were evaluated, and the sizes were compared with those of 16 symptomatic, surgically proved Morton neuromas. The prevalence and diameter of fluid collections in the intermetatarsal bursae were evaluated on the T2-weighted images.Twenty-four Morton neuromas were diagnosed in 21 subjects (prevalence, 30%). The transverse diameter of the neuromas was 3-7 mm (mean, 4.5 mm) versus 4-8 mm (mean, 5.6 mm) in symptomatic subjects; this difference was significant (P = .0075). The prevalence of fluid in the intermetatarsal bursa was 20%, 47%, 49%, and 0% for the first through fourth intermetatarsal spaces. The transverse diameter of the fluid collection was 1-4 mm.The diagnosis of Morton neuroma at MR imaging may be relevant only when the transverse diameter is 5 mm or more and can be correlated to clinical findings. Fluid collections in the first three intermetatarsal bursae with a transverse diameter of 3 mm or less can be considered physiologic.

To evaluate whether positional magnetic resonance (MR) images of the lumbar spine demonstrate nerve root compromise not visible on MR images obtained with the patient in a supine position (conventional MR images).Thirty patients with chronic low back pain unresponsive to nonsurgical treatment and with disk abnormalities but without compression of neural structures were included. Positional MR images were obtained by using an open-configuration, 0.5-T MR imager with the patients seated and with flexion and extension of their backs. The disk and nerve root were related to the body position. Nerve root compression and foraminal size were correlated with the patient's symptoms, as assessed with a visual analogue scale.Nerve root contact without deviation was present in 34 of 152 instances in the supine position, in 62 instances in the seated flexion position, and in 45 instances in the seated extension position. As compared with the supine position, in the seated flexion position nerve root deviation decreased from 10 to eight instances; in the seated extension position, it increased from 10 to 13 instances. Nerve root compression was seen in one patient in the seated extension position. Positional pain score differences were significantly related to changes in foraminal size (P =.046) but not to differences in nerve root compromise.Positional MR imaging more frequently demonstrates minor neural compromise than does conventional MR imaging. Positional pain differences are related to position-dependent changes in foraminal size.

Tendinopathy and rupture of the tendon of the long head of the biceps brachii muscle: evaluation with MR arthrography.M Zanetti, D Weishaupt, C Gerber and J HodlerAudio Available | Share

PURPOSE: To assess the magnetic resonance (MR) imaging appearance of the alar ligaments and joints in the upper cervical spine to determine the prevalence of structural alterations in asymptomatic individuals. MATERIALS AND METHODS: Fifty healthy individuals (31 men, 19 women) with a mean age of 30 years (range, 19–47 years) underwent coronal T1- and T2-weighted and transverse T1-weighted MR imaging. MR findings were analyzed independently by two musculoskeletal radiologists, with disagreements resolved in conference. RESULTS: Alar ligaments were detected in 42 (84%) (left side) and 38 (76%) (right side) of 50 individuals. The majority of ligaments (88%) and joints (58%) of the craniocervical junction (CCJ) were asymmetric. Asymmetry of the joint between C1 and C2 was less frequent (46%). Small amounts of fluid were detected in 8% of CCJ joints and 56% of C1-C2 joints in asymptomatic individuals. CONCLUSION: Asymmetry of alar ligaments, CCJ and C1-C2 facet joints, and joint effusions are common in asymptomatic individuals. The clinical relevance of these MR findings is therefore limited in the identification of the source of neck pain in symptomatic patients.

To prospectively evaluate the accuracy of ultrasonography (US) in depicting fatty atrophy of the supraspinatus (SSP) and infraspinatus (ISP) muscles, with magnetic resonance (MR) imaging as the reference standard.Institutional review board approval and informed consent were obtained. SSP and ISP muscles of 65 consecutive patients (27 women, 38 men; mean age, 53.1 years; range, 28-83 years) with possible rotator cuff tears were evaluated with US in two planes. Visibility of muscle contour, pennate pattern, the central tendon, and muscle echogenicity was assessed by two radiologists. On the basis of these findings, diagnosis of substantial fatty atrophy was made at US. Accuracy, sensitivity, specificity, proportion of over- and underestimations, and interobserver agreement in diagnosis of substantial (grade 2 or greater) muscle atrophy were determined. Fatty atrophy was graded at MR imaging as follows: score of 0 = no intramuscular fat, score of 1 = some fatty streaks, score of 2 = fat evident but less extensive than muscle, score of 3 = fat equal to muscle, and score of 4 = fat more extensive than muscle.For readers 1 and 2, the accuracy of US in depicting fatty atrophy of SSP muscle was 75% (49 of 65) and 72% (47 of 65), sensitivity was 89% (eight of nine) and 100% (nine of nine), and specificity was 73% (41 of 56) and 68% (38 of 56), respectively. For readers 1 and 2, the accuracy of US in depicting fatty atrophy of ISP muscle was 85% (55 of 65) and 80% (52 of 65), sensitivity was 58% (11 of 19) and 63% (12 of 19), and specificity was 96% (44 of 46) and 87% (40 of 46), respectively. Overestimation of SSP muscle atrophy was more common (23% [15 of 65] for reader 1 and 28% [18 of 65] for reader 2) than underestimation (2% [one of 65] for reader 1 and 0% [0 of 65] for reader 2). For readers 1 and 2, overestimation of ISP muscle atrophy was 3% (two of 65) and 9% (six of 65) and underestimation was 12% (eight of 65) and 9% (seven of 65), respectively. Interobserver agreement was moderate for SSP (kappa = 0.55) and substantial for ISP (kappa = 0.71) muscles.US is moderately accurate in the diagnosis of substantial fatty atrophy of the SSP or ISP muscle.

To retrospectively evaluate the appearance of lesions of osseous and soft-tissue structures of the glenohumeral joint on magnetic resonance (MR) images after first-time traumatic posterior shoulder dislocation.The study was institutional review board approved and HIPAA compliant, as appropriate, for the four institutions at which the involved patients were treated. Informed patient consent was obtained, were applicable. Thirty-six male patients (age range, 15-80 years; mean age, 40.2 years) with clinically documented first-time traumatic posterior shoulder dislocation were examined with MR arthrography (18 patients) or conventional shoulder MR imaging (18 patients). Causes of posterior shoulder dislocation were electric shock in one patient, seizure in one patient, and trauma in 34 patients. Hill-Sachs lesions, rotator cuff tears, biceps tendon abnormalities, posterior labrocapsular complex lesions, humeral head translation, and osseous glenoid version angle were evaluated. Spearman rank correlation and Student t test analyses were performed.In 31 (86%) of the 36 patients, a reverse Hill-Sachs lesion was found. Eleven (31%) patients had a reverse osseous Bankart lesion. Twelve full-thickness rotator cuff tears were seen in seven (19%) patients: four supraspinatus tendon, three infraspinatus tendon, and five subscapularis tendon tears. Six (17%) patients had biceps tendon abnormalities. Posterior labrocapsular complex tears were identified in 21 (58%) patients: 10 (48%) with posterior labral sleeve avulsions and 11 (52%) with reverse Bankart lesions. Twenty-seven (75%) patients had a retroverted scaphoglenoid angle (mean, 4.5 degrees ). The mean humeral translation distance relative to the osseous glenoid fossa was -4.8 mm; in 33 (92%) patients, this distance was translated posteriorly.The MR appearance of traumatic posterior shoulder dislocation was characterized by reverse Hill-Sachs lesions in 86% of patients and posterocaudal labrocapsular lesions in nearly 60% of patients. Full-thickness rotator cuff tears were seen in approximately 20% of patients.

PURPOSE: To determine the prevalence of articular cartilage lesions in patients with subacromial impingement syndrome and to assess the diagnostic effectiveness of magnetic resonance (MR) arthrography in detecting such cartilage abnormalities. MATERIALS AND METHODS: MR arthrographic images obtained in 52 consecutive patients (mean age, 45.8 years; age range, 17-73 years; 26 male and 26 female patients) were retrospectively evaluated for glenohumeral cartilage lesions. Two experienced musculoskeletal radiologists who were blinded to the arthroscopy report independently analyzed the articular cartilage. Humeral and glenoidal cartilage were assessed separately. The lesions were graded as either subtle or marked. Arthroscopic findings were the standard of reference. Sensitivity, specificity, accuracy, and interobserver agreement were calculated. RESULTS: At arthroscopy, humeral cartilage lesions were found in 15 patients (frequency, 29%). Four lesions were subtle, and 11 were marked. Cartilage lesions of the glenoid were less frequent (eight patients; frequency, 15%): Three were subtle, and five were marked. For reader 1 and reader 2, respectively, sensitivity of MR arthrography for humeral cartilage lesions was 53% and 100%, specificity was 87% and 51%, and accuracy was 77% and 65%; sensitivity for glenoidal cartilage lesions was 75% and 75%, specificity was 66% and 63%, and accuracy was 67% and 65%. Interobserver agreement for the grading of cartilage lesions with MR arthrography was fair (humeral lesions, κ = 0.20; glenoidal lesions, κ = 0.27). CONCLUSION: Glenohumeral cartilage lesions are found in up to one third of patients referred for MR arthrography for subacromial impingement syndrome. The performance of MR arthrography in the detection of glenohumeral cartilage lesions is moderate. © RSNA, 2002

To evaluate prospectively, on magnetic resonance (MR) images in volunteers with asymptomatic ankles, various features of anatomic variants that are potentially associated with peroneal tendon disorders.The study had institutional review board approval; informed consent was obtained from each volunteer. The prevalence of accessory peroneus quartus muscles, the location of the muscle-tendon junction of the peroneus brevis muscle, the prevalence and size of the peroneal tubercle and the retrotrochlear eminence, and the shape of the retromalleolar fibular groove were evaluated on MR images in 65 volunteers with asymptomatic ankles (35 women, 30 men; age range, 23-70 years; median age, 45 years). MR images were analyzed by two radiologists in consensus. The relationship between anatomic features and age and sex was analyzed by using Spearman rank correlation and the Wilcoxon rank sum test.A peroneus quartus muscle was identified in 11 (17%) ankles. Ninety percent of the musculotendinous junctions of the peroneus brevis muscle were located in a range between 27 mm proximal to and 13 mm distal to the fibular tip (median, 0 mm). A peroneal tubercle was identified in 36 (55%) ankles. Ninety percent of all peroneal tubercles were 4.6 mm or smaller (median height, 2.9 mm). A retrotrochlear eminence was seen in all ankles (median, 3.0 mm; 90% were 4.6 mm or smaller). The retromalleolar groove was concave in 18 (28%), flat in 28 (43%), convex in 12 (18%), and irregular in seven (11%) volunteers. A significant difference (P = .04) for the height of the retrotrochlear eminence was found between men (median, 3.4 mm) and women (median, 2.5 mm). All other P values were greater than .05.Anatomic variants thought to predispose individuals to peroneal tendon disorders can be seen in volunteers with asymptomatic ankles.

To retrospectively evaluate imaging characteristics of surgically proved sublabral recesses and labral tears in the anterior portion of the acetabulum at magnetic resonance (MR) arthrography.Institutional review board approval was obtained; informed consent was waived. The study included 57 patients (36 women [mean age, 37 years], 21 men [mean age, 32 years]) who underwent MR arthrography and either surgery or arthroscopy as reference standard. On MR images, location of sublabral contrast material interposition and depth, shape, and extension into the labral substance of contrast material interpositions were described. Abnormal labral signal intensity (areas of high signal intensity), acetabular cartilage lesions, osseous abnormalities, and perilabral cysts were noted. Mann-Whitney U and Fisher exact tests were performed; interobserver agreement was calculated (kappa statistic and intraclass correlation coefficient).Surgical procedures revealed that 10 (18%) of 57 patients had recesses and 44 (77%) of 57 had tears. Locations of recesses and tears, respectively, were as follows: seven and none, in the 8-o'clock position; two of each, in the 9-o'clock position; one and 22, in the 10-o'clock position; and none and 20, in the 11-o'clock position. None of the recesses extended into the substance of the labrum or through the full thickness of the labral base; 51% (22 of 43) of tears extended into the substance and 49% (21 of 43) of tears extended along the entire labral base. Shape of sublabral contrast material interposition was linear in five (83%) of six recesses and 21 (49%) of 43 tears. Recesses were not associated with abnormal signal intensity of the labrum, cartilage lesions, osseous abnormalities, or perilabral cysts. Of 43 tears, 32 (74%) were associated with abnormal signal of the labrum; 23 (53%), with cartilage damage; 11 (26%), with osseous abnormalities; and eight (19%), with perilabral cysts.Recesses occur as normal variants in the anteroinferior part of the acetabulum. Location in the 8-o'clock position, linear shape of contrast material interposition, partial separation of the labrum, and absence of perilabral abnormalities are characteristics of a recess.

Magnetic resonance (MR) imaging for chronic wrist pain is challenging. Correct assessment of the triangular fibrocartilage, hyaline cartilage, ligaments, and tendons has become mandatory for comprehensive decision making in wrist surgery. The MR technique, potential and limits of MR imaging in patients with chronic wrist pain will be discussed. MR arthrography with injection of gadolinium-containing contrast material into the distal radioulnar joint is suggested for evaluation of the triangular fibrocartilage. The clinically meaningful ulnar-sided peripheral tears are otherwise hard to diagnose. The diagnostic performance of MR imaging for interosseous ligament tears varies considerably. The sensitivity for scapholunate ligament tears is consistently better than for lunotriquetral ligament tears. Gadolinium-enhanced MR imaging is considered to be the best technique for detecting established avascularity of bone, but the assessment of the MR results remains challenging. Most cases of ulnar impaction syndrome have characteristic focal signal intensity changes in the ulnar aspect of the lunate. Avascular necrosis of the lunate (Kienböck’s disease) is characterized by signal changes starting in the proximal radial aspect of the lunate. MR imaging is extremely sensitive for occult fractures. Questions arise if occult posttraumatic bone lesions seen on MR images only necessarily require the same treatment as fractures evident on plain films or computed tomography (CT) images. MR imaging and ultrasound are equally effective for detecting occult carpal ganglia. Carpe bossu (carpal boss) is a bony protuberance of a carpometacarpal joint II and III which may be associated with pain.

To prospectively evaluate the accuracy of magnetic resonance (MR) imaging of the knee performed by using a three-dimensional (3D) isovoxel sequence involving an acquisition time of approximately 3 minutes, with surgery as the reference standard.The study was institutional review board approved. Written informed consent was obtained from all patients. Thirty knees of 29 patients (14 women, 15 men; mean age, 41 years) were prospectively examined by using a 3D isovoxel true fast imaging with steady-state precession (FISP) sequence with water excitation and secondary multiplanar reformations. All patients underwent arthroscopy within 12 days after true FISP MR imaging. Two blinded readers evaluated the MR images. Accuracy for detection of cartilage defects and anterior cruciate ligament (ACL) and meniscal tears, interobserver agreement, and intermethod agreement were calculated.Overall sensitivity, specificity, and accuracy of isovoxel true FISP imaging for the diagnosis of cartilage defects were 45%, 83%, and 76%, respectively, for reader 1 and 63%, 82%, and 83%, respectively, for reader 2. Averaged (for readers 1 and 2) sensitivity, specificity, and accuracy of isovoxel true FISP imaging were, respectively, 80%, 95%, and 90% for diagnosis of ACL tear; 100%, 82%, and 90% for diagnosis of medial meniscal tear; and 83%, 83%, and 83% for diagnosis of lateral meniscal tear. The standard MR sequences used at the authors' institution had overall sensitivities, specificities, and accuracies of 39%, 83%, and 71%, respectively, for reader 1 and 37%, 85%, and 76%, respectively, for reader 2. Averaged sensitivity, specificity, and accuracy of the standard MR sequences were, respectively, 70%, 100%, and 90% for diagnosis of ACL tear; 96%, 77%, and 85% for diagnosis of medial meniscal tear; and 83%, 77%, and 78% for diagnosis of lateral meniscal tear.The diagnostic performance of knee MR imaging performed by using a 3D water excitation isovoxel true FISP sequence and an imaging time of approximately 3 minutes is comparable to the diagnostic performance of the MR sequences used as standards at the authors' institution.

To prospectively compare the accuracy of three-dimensional (3D) water-excitation (WE) true fast imaging with steady-state precession (FISP) in the diagnosis of articular cartilage defects with that of sequences commonly used to image the knee, with arthroscopy or surgery as the reference standard.This study protocol was institutional review board approved. Written informed consent was obtained from all patients. Thirty knees in 29 patients (mean age, 56 years; range, 18-86 years) were prospectively evaluated by using sagittal 3D WE true FISP with two section thicknesses (1.7 mm [true FISPthin] and 3.0 mm [true FISPthick]), two-dimensional (2D) intermediate-weighted spin-echo with fat saturation, 2D fast short inversion time inversion-recovery, 3D WE double-echo steady-state, and 3D fat-saturated fast low-angle shot sequences. Cartilage defects were graded on magnetic resonance images and during surgery with a modified Noyes scoring system. Contrast-to-noise ratio (CNR) and CNR efficiency were calculated. Sensitivity, specificity, and accuracy were assessed. Interobserver agreement was determined with kappa statistics, and quantitative results were evaluated with the Wilcoxon signed rank test.The performance of 3D WE true FISPthick (sensitivity, specificity, and accuracy, respectively, were 52%, 93%, and 71% for reader 1 and 65%, 88%, and 76% for reader 2) and 3D WE true FISPthin (sensitivity, specificity, and accuracy, respectively, were 58%, 94%, and 75% for reader 1 and 63%, 80%, and 71% for reader 2) sequences was no different than that of other sequences in the detection of circumscribed defects. Three-dimensional WE true FISP sequences had a significantly (P<.0033) higher CNR and CNR efficiency between cartilage and fluid than the corresponding sequences with the same section thickness.Three-dimensional WE true FISP enables high contrast between joint fluid and articular cartilage and a diagnostic performance that is comparable with that of standard sequences.

To prospectively characterize the spin-echo magnetic resonance (MR) imaging appearance of the medial collateral ligament (MCL) complex of the ankle in asymptomatic volunteers.The study was approved by institutional review board. Informed consent was obtained. MR images in 56 asymptomatic subjects (29 women, 27 men; mean age, 40.7 years; range, 23-60 years) were analyzed by two musculoskeletal radiologists. Visibility and signal intensity characteristics were analyzed for deep (anterior and posterior tibiotalar ligaments [TTLs]) and superficial (tibionavicular ligament [TNL], tibiospring ligament [TSL], and tibiocalcaneal ligament [TCL]) components of the MCL complex. Thickness of ligaments was compared between sexes (Mann-Whitney U test). Associations between age and variables of signal intensity characteristics and morphology were evaluated with Kruskal-Wallis test.Anterior and posterior TTLs, TNL, TSL, and TCL were visible in 31 (55%), 56 (100%), 31 (55%), 56 (100%), and 49 (88%) subjects, respectively. On T1-weighted images, anterior and posterior TTLs, TNL, TSL, and TCL were more commonly of intermediate signal intensity than hypointense (77%, 100%, 93%, 50%, and 73% of subjects, respectively); on T2-weighted images, they were commonly hypointense (55%, 52%, 42%, 75%, and 78% of subjects, respectively). On T2-weighted images, posterior TTL had a striated appearance that was significantly associated with age (P = .004) in 89% of subjects: In subjects younger than 45 years, this striated appearance was present. On T1-weighted images, striation was present in 48% of subjects. Striation was uncommon in remaining ligaments. Mean thickness and range were 1.5 mm and 1-4 mm (anterior TTL), 8.2 mm and 6-11 mm (posterior TTL), 1.6 mm and 1-2 mm (TNL), 2.0 mm and 1-4 mm (TSL), and 1.2 mm and 1-3 mm (TCL). TNL (P = .001) and TSL (P = .003) were significantly thicker in men than in women.In asymptomatic volunteers, posterior TTL and TSL were always visible, but anterior TTL and TNL are only seen in approximately half of subjects. Posterior TTL has a typically striated appearance.

Purpose: To prospectively evaluate pain and other side effects after magnetic resonance (MR) arthrography. Materials and Methods: Institutional review board approval and patient informed consent were obtained. MR arthrography was performed in 1085 patients. In 1011 patients, 2 mmol/L gadopentetate dimeglumine was injected. In patients whose wrists were examined, 5 mmol/L gadoterate dimeglumine was injected. Pain was measured directly after injection, 4 hours after injection, 1 day [18–30 hours] after injection, and 1 week [6–8 days] after injection and compared with pain at baseline (before contrast material was injected). A visual analogue scale or verbal rating scale (score range, 0–10) was used to measure pain. When increased pain persisted at the end of the observation period, additional assessment was performed to exclude infection. Evaluated factors with a potential effect on pain were time after injection, joint type, contrast agent volume, patient age and sex, and radiologist experience. Repeated measures analysis of variance was used. Results: Mean pain increase was most pronounced 4 hours after injection (P < .0001). This increase was most pronounced in the hip, followed by the elbow, knee, wrist, ankle, and shoulder. (Differences between joints were not significant [P = .26].) Pain scores returned to baseline levels 1 week after injection. Patients younger than 30 years had more pronounced pain than did patients in other age groups at all time points (P = .044). Joint type, contrast agent volume (P = .44), patient sex (P = .29), and radiologist experience (P = .10) did not significantly affect pain scores. No patient had infection or any other severe side effect. Besides joint pain, minor side effects included pressure, headache, muscle ache, swollen hand, fatigue, vertigo, increased blood glucose level, and pruritus. Conclusion: MR arthrography temporarily increases joint-related pain. Such pain depends on patient age but not on joint type, contrast material volume, patient sex, or radiologist experience. © RSNA, 2009

Purpose To prospectively evaluate the normal variability of ligaments, plicae, and the posterior capitellum on conventional magnetic resonance (MR) images of the elbow in asymptomatic volunteers. Materials and Methods The study was approved by the institutional ethics board, and informed consent was obtained from all subjects. MR imaging was performed at 1.5 T in 60 asymptomatic volunteers (30 women, 30 men; age range, 22–51 years; median age, 32.8 years) by using the following five pulse sequences: transverse T1-weighted spin-echo, sagittal T2-weighted fast spin-echo, coronal fast spin-echo short-inversion-time inversion recovery, transverse intermediate-weighted with fat saturation, and coronal three-dimensional water-excitation true fast imaging with steady-state precession. The visibility (completely visible over the entire course, partially visible, or not visible) and signal intensity characteristics (hypointense or hyperintense to muscle, homogeneous signal intensity vs striation) of the elbow ligaments and plicae were evaluated by three independent readers. The presence of pseudodefects at the posterior capitellum was determined. The dimensions of all structures were measured by two independent readers. Results The anterior ulnar collateral ligament (UCL) and radial collateral ligament (RCL) were visible over their entire course in all 60 subjects (100%). The posterior UCL, lateral UCL, and annular ligament (AL) were completely visible in 58 (97%), 51 (85%), and 59 (98%) of the 60 subjects, respectively, and partially visible in the remaining subjects. Increased signal intensity with fluid-sensitive sequences was found in the anterior UCL in nine of the 60 subjects (15%), posterior UCL in four subjects (7%), RCL in one subject (2%), lateral UCL in six subjects (10%), and AL in one subject (2%). The median thickness and 90th percentile were 2.5 and 3.5 mm, respectively, for the anterior UCL, 1.0 and 1.7 mm for the posterior UCL, 1.9 and 2.8 mm for the RCL, 2.3 and 3.8 mm for the lateral UCL, and 1.0 and 1.3 mm for the AL. A posterolateral plica (median dimension, 4.3 × 1.9 × 3.9 mm) was found in 59 of the 60 subjects (98%), whereas a posterior plica (median dimension, 1.8 × 1.4 mm) could be detected in only 20 (33%). A pseudodefect of the capitellum was noted in 51 of the 60 subjects (85%). Conclusion The elbow ligaments and the posterolateral plica are consistently visible on conventional MR images of asymptomatic subjects. Most normal ligaments are thinner than 4 mm, and most plicae are thinner than 3 mm. © RSNA, 2010

This Report summarizes the results of the activities in 2012 and the first half of 2013 of the LHC Higgs Cross Section Working Group. The main goal of the working group was to present the state of the art of Higgs Physics at the LHC, integrating all new results that have appeared in the last few years. This report follows the first working group report Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002) and the second working group report Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002). After the discovery of a Higgs boson at the LHC in mid-2012 this report focuses on refined prediction of Standard Model (SM) Higgs phenomenology around the experimentally observed value of 125-126 GeV, refined predictions for heavy SM-like Higgs bosons as well as predictions in the Minimal Supersymmetric Standard Model and first steps to go beyond these models. The other main focus is on the extraction of the characteristics and properties of the newly discovered particle such as couplings to SM particles, spin and CP-quantum numbers etc.

The way the hip joint is imaged has changed in the past few years as a result of new discoveries in the biomechanics of the hip joint and the rapid developments in hip-preserving surgery. This review discusses technical advances made in the field of hip imaging, covering the roles of radiography, computed tomography, sonography and magnetic resonance (MR) imaging, as well as their limitations. New insight into anatomy and pathogenesis can be useful for the diagnosis of hip abnormalities and in treatment planning. While radiographs are the basis of any imaging of the hip, MR imaging is paramount in the evaluation and preoperative planning of patients suspected of having femoroacetabular impingement, especially when assessing geometrical deformities of the proximal femur. Damage patterns of labrum and cartilage in patients with femoroacetabular impingement are described, as well as new techniques of cartilage MR imaging that might allow the detection of cartilage degeneration before macroscopic defects are formed. Finally, new data on structural variants of the hip joint and pitfalls in imaging of the hip joint are reviewed. © RSNA, 2012

Background: We hypothesized that patients undergoing nonoperative treatment for asymptomatic or minimally symptomatic osteochondral lesions of the talus (OLTs) would not deteriorate clinically or radiologically over time. Methods: Forty-eight patients (mean age = 48 years; range, 13-78 years) with an OLT confirmed by magnetic resonance imaging (MRI) who had not undergone ankle joint surgery were retrospectively reviewed. All patients were evaluated after a minimum follow-up of 2 years (mean = 52 months; range, 27-124 months). All patients filled out an individual questionnaire and underwent a physical and radiographic assessment (radiograph and hindfoot MRI). Results: At final follow-up, 43 ankles (86%) in 41 patients were pain-free (visual analogue scale [VAS] 0, n = 12) or less painful (VAS 1-3, n = 31). Radiographically, osteoarthritis was absent in 47%, and grade 1 and 2 osteoarthritis each were found in 27% (van Dijk classification). Magnetic resonance imaging revealed no substantial progression in staging or lesion size. Pain at time of follow-up correlated with the depth of the lesion at initial MRI ( P &lt; .05) and with subchondral cyst formation and presence or change of bone marrow edema at follow-up MRI ( P &lt; .05). Conclusion: Minimally symptomatic OLTs did not appear to progress or worsen over time when treated nonoperatively. Level of Evidence: Level IV, case series.

The spring ligament complex is an important stabilizer of the medial ankle, together with the posterior tibial tendon (PTT) and the deltoid ligament complex. Lesions in these stabilizers result in acquired adult flatfoot deformity. The spring ligament complex includes three ligaments: the superomedial calcaneonavicular ligament, the medioplantar oblique calcaneonavicular ligament, and the inferoplantar longitudinal calcaneonavicular ligament. Normal MR imaging anatomy of the spring ligament complex and the PTT are described and illustrated in detail. Isolated lesions of the spring ligament complex are rare. In most cases, spring ligament complex lesions are secondary to PTT dysfunction. The best criteria for an injury of the clinically relevant superomedial calcaneonavicular ligament are increased signal on proton-density or T2-weighted sequences with thickening (> 5 mm), thinning (< 2 mm), or partial or complete discontinuity. A thickened ligament can be simulated by the gliding layer between the PTT and the superomedial calcaneonavicular ligament (thickness: 1–3 mm). The most common location of injury is the superior and distal portion of the superomedial calcaneonavicular ligament. A lesion seen by the orthopedic foot surgeon at the junction between the tibiospring ligament and the superomedial portion of the calcaneonavicular ligament is commonly classified as a spring ligament injury. In addition, an overview of MR imaging findings in different stages of the acquired adult flatfoot deformity is provided.

The objective of our study was to compare MRI findings in the sacroiliac joints of postpartum women (as a model of mechanical changes) and women with known axial spondyloarthritis (as an inflammatory model).For this prospective multicenter age-matched, case-control study, sacroiliac joint MRI examinations of 30 healthy women (mean age, 34.0 years) in the early postpartum period (mechanical group) and 30 age-matched women (mean age, 33.8 years) with known axial spondyloarthritis (retrospective inflammatory group) were compared. Blinded to clinical information, readers assessed MR images using the following scoring systems: Spondyloarthritis Research Consortium of Canada (SPARCC) MRI index, Berlin method, Assessment of Spondyloarthritis International Society (ASAS) criteria, and SPARCC MRI structural score. Descriptive statistics as percentages of the different findings (i.e., bone marrow edema [BME], erosion, fatty bone marrow replacement, backfill, ankylosis) and scores between groups and between delivery modes were compared.In the postpartum group, 63.3% (19/30) of women showed BME around the sacroiliac joints compared with 86.7% (26/30) of women in the spondyloarthritis group (based on ASAS criteria). Erosions were uncommon in the postpartum group (10.0% [3/30] postpartum vs 56.7% [17/30] spondyloarthritis). Fatty bone marrow replacement, backfill, and ankylosis were not seen in the postpartum group. In subjects with positive MRI findings for sacroiliitis based on ASAS criteria, the SPARCC MRI index (mean ± SD, 13.6 ± 14.5 vs 13.0 ± 10.7; p = 0.818) and Berlin method (4.5 ± 3.0 and 5.5 ± 3.5, p = 0.378) were not different between the postpartum and spondyloarthritis groups. Scores were not different between birth modalities.Pregnancy-induced BME at the sacroiliac joints, as a result of prolonged mechanical stress, was present in 63.3% of women who underwent MRI during the early postpartum period and may mimic sacroiliitis of axial spondyloarthritis.

We show how to deal with uncertainties on the Standard Model predictions in an agnostic new physics search strategy that exploits artificial neural networks. Our approach builds directly on the specific Maximum Likelihood ratio treatment of uncertainties as nuisance parameters for hypothesis testing that is routinely employed in high-energy physics. After presenting the conceptual foundations of our method, we first illustrate all aspects of its implementation and extensively study its performances on a toy one-dimensional problem. We then show how to implement it in a multivariate setup by studying the impact of two typical sources of experimental uncertainties in two-body final states at the LHC.

The purpose of our study was to evaluate the role of MR imaging in patients with suspected Morton's neuroma and to assess the value of various MR sequences in this diagnosis.Thirty-two consecutive patients with suspected Morton's neuroma were studied using a 1.0-T MR scanner. Axial T1- and T2-weighted spin-echo, short inversion time inversion recovery, and enhanced T1-weighted fat-suppressed spin-echo images were obtained on each patient. Eighteen intermetatarsal spaces in 16 of the 32 patients were evaluated surgically. Contrast-to-noise ratios for Morton's neuroma versus surrounding fat were calculated and standardized for imaging times.In 15 of 18 intermetatarsal spaces, a Morton's neuroma was surgically proven. Thirteen true-positive, two false-negative, three true-negative, and no false-positive MR diagnoses were given. In six of 15 proven neuromas, the clinical examiner was not able to identify the correct intermetatarsal space. The MR diagnoses in the 16 remaining patients who did not undergo surgery were Morton's neuroma (n = 8), stress fracture (n = 1), foreign body reaction (n = 1), tendon sheath ganglion (n = 1), postoperative changes (n = 2), and no abnormality (n = 3). Standardized contrast-to-noise ratios (+/- SD) were 2.42 +/- 0.72 for T1-weighted images; 1.43 +/- 1.13 for T2-weighted images; 1.26 +/- 1.47 for short inversion time inversion recovery images; and 0.83 +/- 0.59 gadolinium-enhanced fat-suppressed images. The differences were statistically significant for the T1-weighted spin-echo images versus the three other sequences (p = .001-.018), but not among the other sequences (p = .209-.710).MR imaging is accurate in diagnosing Morton's neuroma and may be important for correct localization. A limited examination employing axial T1-weighted spin-echo images is adequate; additional sequences should be employed only for differential diagnosis.

Abstract The objective of this study was to assess the value of adding MR arthrography to standard MRI for patients with chronic wrist disorders. Thirty consecutive patients (age range, 19–73 years; mean, 36.2 years) were included in the investigation. The images were evaluated blindly and separately by two radiologists with regard to lesions of the scapholunate (SL) and lunotriquetral (LT) ligaments and the triangular fibrocartilage (TFC). Conventional two‐ or three‐compartment arthrography was used as the standard of reference. For TFC lesions, standard MR images had a sensitivity of 92.3% (reader 1) and 84.6% (reader 2) and a specificity of 41.2% (reader 1) and 52.9% (reader 2). For MR arthrography, sensitivity was 84.6% (reader 1) and 84.6% (reader 2) and specificity was 88.2% (reader 1) and 100% (reader 2). For SL ligament tears, standard MRI had a sensitivity of 33.3% (reader 1) and 11.1% (reader 2) and a specificity of 47.6% (reader 1) and 57.1% (reader 2). For MR arthrography, sensitivity was 66.7% (reader 1) and 55.6% (reader 2) and specificity was 52.4% (reader 1) and 81.0% (reader 2). For LT ligament tears, standard MRI had a sensitivity of 28.6% (reader 1) and 35.7% (reader 2) and a specificity of 93.8% (reader 1) and 81.3% (reader 2). For MR arthrography, sensitivity was 35.7% (reader 1) and 23.1% (reader 2) and specificity was 93.8% (reader 1) and 94.1% (reader 2). In conclusion, the diagnostic performance of MRI in suspected lesions of the TFC and the SL and LT ligaments is improved by adding MR arthrography to the standard examination.

To use magnetic resonance (MR) imaging to assess the anatomy of the spring ligament complex (SLC) in cadaveric feet and to prospectively evaluate the MR imaging depiction of this complex in asymptomatic subjects.Cadaveric feet were obtained and used according to institutional guidelines and with institutional approval and consent from the donors (before death) or the appropriate family members. Healthy volunteers were examined, with institutional review board approval and informed consent from each volunteer. MR imaging findings of the SLC in five cadaveric feet were analyzed and correlated with the findings in dissected foot specimens. Then, the MR imaging findings in the feet of 78 asymptomatic subjects were analyzed. For all three parts of the SLC, visibility, optimal imaging plane, and signal intensity characteristics were analyzed. The thicknesses of all SLC parts were measured. The measurements obtained in men and women were compared by using the Mann-Whitney U test, and Pearson correlation coefficients for associations between ligament thickness and subject age and sex were calculated.In the cadaveric feet, MR imaging enabled differentiation of all three parts of the SLC. The superomedial calcaneonavicular ligament (CNL) was visible in all; the medioplantar oblique CNL, in 60; and the inferoplantar longitudinal CNL, in 71 volunteers. The superomedial CNL had a mean thickness of 3.2 mm, was best seen on transverse oblique or coronal MR images, and had mainly intermediate signal intensity on T1-weighted images and low signal intensity on T2-weighted images. The medioplantar oblique CNL had a mean thickness of 2.8 mm, was best seen on transverse oblique MR images, and had mainly a typical striated appearance on T1- and T2-weighted images. The inferoplantar longitudinal CNL was the thickest (mean thickness, 4.0 mm), was best seen on coronal MR images, and had mainly intermediate signal intensity on T1-weighted images and variable signal intensity on T2-weighted images. Women had significantly thinner superomedial (mean thickness, 3.3 vs 3.5 mm; P = .015, Mann-Whitney U test) and inferoplantar longitudinal (mean thickness, 3.8 vs 4.2 mm; P = .02) CNLs than men. There was no significant correlation between ligament thickness and subject age.The superomedial and inferoplantar longitudinal CNLs are consistently visible portions of the SLC. The medioplantar oblique ligament is thinner, is seen less consistently, and has mainly a characteristic striated MR imaging appearance.

Muscle atrophy is a known consequence of muscle disuse, muscle denervation and tendon tear. Whereas after nerve injury muscle atrophies in the denervated area, the distribution of muscle atrophy following tear of its tendon is not known. Standardized MRI scans of 64 consecutive, painful shoulders were evaluated for supraspinatus tendon tearing, myotendinous retraction, supraspinatus muscle atrophy, fatty infiltration, ratio of the scapular (deep) and fascial (superficial) muscle area ("symmetry") and position of the central tendon within the supraspinatus fossa. There were thirteen shoulders with no and eleven shoulders with partial thickness supraspinatus tendon tears. In the forty cases with full thickness tendon tear, there was significant muscle atrophy and fatty infiltration. Atrophy of the fascial muscle portion was 43%, on the bony side it was 9% (p<0.005). The position of the central tendon within the supraspinatus fossa, was unaltered. Muscular changes following tendon tear occur highly asymmetrically: the muscle portion originating from the fascia primarily atrophies, the portion originating from the scapula primarily undergoes fatty infiltration. Muscular changes are not simply a consequence of muscle disuse, but dependent on architectural changes in the muscle.

The purposes of this study were to evaluate the prevalence and determine the size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections on MR images of asymptomatic knees.MR images of 102 asymptomatic knees were evaluated with regard to the prevalence of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections. The MR examinations were performed in patients (mean age, 42.8 years; age range, 18-73 years) with clinically suspected meniscal lesions in the contralateral knee. The craniocaudal, anteroposterior, and mediolateral diameters of detectable abnormal fluid collections were measured.Medial meniscal cysts (mean size [craniocaudal x anteroposterior x mediolateral], 9 x 6 x 13 mm) were found in four asymptomatic knees. Neither lateral meniscal cysts nor ganglionic cysts of the cruciate ligaments were identified. Twenty-six synovial cysts of the popliteal space (Baker's cyst)-consisting of 11 gastrocnemius portions (mean size, 19 x 8 x 10 mm) and 15 semimembranosus portions (mean size, 20 x 7 x 9 mm)-were found in 19 knees. Twenty-four (92%) of these cysts had a maximal diameter of 30 mm or less. Fluid-filled bursae were found in 49 knees. The deep infrapatellar bursa was most commonly involved (42 knees; mean size, 6 x 3 x 5 mm). Fluid-filled anserine bursae (mean size, 27 x 12 x 10 mm) were detected in five knees.Meniscal cysts may be present in asymptomatic knees, at least on the medial side. Synovial cysts of the popliteal space can be found in approximately one fifth of asymptomatic knees. Their maximal diameter is usually smaller than 30 mm.

The purpose of this study was to assess the diagnostic value of MR arthrography in detecting a lesion of the common insertion of the coracohumeral and the superior glenohumeral ligaments and the superior border of the subscapularis tendon (pulley lesion), which predisposes to biceps tendon subluxation and subsequent degeneration.Parasagittal T1-weighted turbo spin-echo and axial gradient-echo (three-dimensional fast imaging with steady state-precession [FISP]) MR arthrographic images were obtained in 14 patients with surgically confirmed pulley lesions and in 10 patients with an intact pulley. Various MR arthrographic signs potentially associated with a pulley lesion were evaluated separately and independently in a blinded fashion by two radiologists.Abnormalities of the superior border of the subscapularis tendon on axial and parasagittal images, extra-articular contrast collection, and biceps tendon subluxation were the MR findings of a pulley lesion. The coracohumeral and superior glenohumeral ligaments were not readily visible in all patients and were not helpful in diagnosing pulley lesions in this study. The overall sensitivity for detecting a pulley lesion by MR arthrography was 86% and 93% for readers 1 and 2, with a specificity of 100% and 80% and an accuracy of 92% and 87% (kappa = 0.75).Based on the authors' experience, MR arthrography is valuable in detecting lesions of the reflection pulley of the long biceps tendon, although differentiation from an isolated lesion of the superior border of the subscapularis tendon may not be possible.

To evaluate proton magnetic resonance (MR) spectroscopy in the assessment of lipid content of the supraspinatus muscle in asymptomatic volunteers and patients with supraspinatus tendon lesions.Single-voxel proton MR spectroscopy was used to assess lipid content of the supraspinatus muscle in asymptomatic volunteers (n = 30) and patients with partial-thickness supraspinatus tendon tears (n = 30), newly diagnosed full-thickness supraspinatus tendon tears (n = 30), and chronic full-thickness supraspinatus tendon tears (n = 30). The apparent lipid content of the supraspinatus muscle measured with proton MR spectroscopy was related to its appearance on sagittal-oblique T1-weighted spin-echo MR images (grades 0-4). One-way analysis of variance was performed to test for significant differences, and the Tukey honestly significant difference procedure was performed for post hoc comparisons.Mean apparent lipid content was 13.7% (95% confidence interval [CI]: 11.5%, 15.8%) for asymptomatic volunteers, 29.5% (95% CI: 25.1%, 34.0%) for patients with partial-thickness tears, 48.6% (95% CI: 41.3%, 55.9%) for patients with full-thickness tears, and 66.1% (95% CI: 57.7%, 74.5%) for patients with chronic tears. Values were significantly different (analysis of variance, P <.001; P <.001-.002 for all post hoc pairwise comparisons). Mean apparent lipid content for the supraspinatus muscle was as follows: grade 0, 19.6% (95% CI: 16.7%, 22.6%); grade 1, 36.8% (95% CI: 33.2%, 40.4%); grade 2, 53.6% (95% CI: 43.1%, 64.2%); grade 3, 67.5% (95% CI: 52.6%, 82.3%); and grade 4, 79.2% (95% CI: 73.2%, 85.3%). With analysis of variance (P <.001), all post hoc pairwise comparisons were significant (P </=.001) except between grades 2 and 3 (P =.112) and between grades 3 and 4 (P =.261). In 14 (25%) subjects who had grade 0 appearance on T1-weighted images, lipid content values were greater than the upper range of values in the volunteers.Proton MR spectroscopy is suitable in the assessment of apparent lipid content of rotator cuff muscles.

Although central tears of the triangular fibrocartilage are easily seen on imaging, peripheral tears of the ulnar attachment are frequently missed. The aim of this study was to evaluate the accuracy of MR arthrography of the distal radioulnar joint in depiction of peripheral tears of the triangular fibrocartilage.Forty-one patients (18 women, 23 men; mean age, 38 years; age range, 18-60 years) underwent MR arthrography and wrist arthroscopy. For MR arthrography, iopamidol (300 mg I/mL) and gadopentetate dimeglumine (4 mmol/L) were injected into the distal radioulnar joint. Consensus review of both MR arthrograms and conventional arthrograms was performed by two experienced musculoskeletal radiologists. Presence or absence of communicating and noncommunicating tears of the ulnar attachment of the triangular fibrocartilage was recorded. Arthroscopy was used as the standard of reference for determining sensitivity, specificity, and accuracy in detection of tears of the ulnar attachment.At MR arthrography, communicating tear of the ulnar attachment was diagnosed in three patients, noncommunicating tear in 19 patients, and normal attachment in 19 patients. Arthroscopy revealed peripheral tear of the triangular fibrocartilage in all three patients with communicating tear, in 14 of 19 patients with noncommunicating tear, and in three of 19 patients with normal attachment. The sensitivity was 85% (17/20), specificity was 76% (16/21), and accuracy was 80% (33/41).MR arthrography of the distal radioulnar joint is accurate in depiction of peripheral tears of the ulnar attachment of the triangular fibrocartilage. These tears often appear as noncommunicating tears extending from the distal radioulnar joint into the triangular fibrocartilage.

To compare short inversion time inversion-recovery (STIR) and T1-weighted contrast material-enhanced fat-suppressed spin-echo magnetic resonance (MR) sequences for depiction of bone marrow abnormalities of the foot and ankle.Fifty-one consecutive patients with bone marrow abnormalities depicted on turbo STIR images were examined with additional T1-weighted contrast-enhanced (0.1 mmol/kg gadopentetate dimeglumine) MR imaging with fat suppression. Volume and signal difference-to-noise ratio (SDNR) were measured. An additional qualitative analysis was performed by two experienced musculoskeletal radiologists to correlate the presence or absence of ill-defined edema-like zones, well-defined zones, and cystlike zones. Diagnoses determined with MR findings with each sequence were compared with the results of a review panel. Correlation coefficients (r(2)) and paired t tests were calculated for all measurements. Agreement percentages and kappa values were calculated for inter- and intraobserver reproducibility.Regarding volume of bone marrow abnormalities, a high correlation (r(2) = 0.98) of both sequences was found. SDNR was substantially higher on T1-weighted contrast-enhanced images than on STIR images (mean, 125.9 vs 95.4; P <.001). The qualitative analysis demonstrated identical imaging patterns with both sequences in 96% (79 of 82, kappa = 0.38) of ill-defined zones, in 88% (72 of 82, kappa = 0.76) of well-defined zones, and in 98% (80 of 82, kappa = 0.84) of cystlike zones. Interobserver reproducibility of the three imaging patterns was similar for both sequences. The kappa values for these three zones with STIR sequence were 0.55, 0.68, and 0.69, and those for the T1-weighted contrast-enhanced MR sequence were 0.49, 0.73, and 0.58, respectively. Diagnoses determined with MR findings were equal with both sequences in 94% (80 of 85) of involved bones.STIR images and T1-weighted contrast-enhanced fat-suppressed MR images demonstrate almost identical imaging patterns, and diagnoses determined with these findings show little difference.

The purpose of this study was to evaluate the femoral component rotation in a small subset of patients who had developed arthrofibrosis after mobile-bearing total knee arthroplasty (TKA). Arthrofibrosis was defined as flexion less than 90 degrees or a flexion contracture greater than 10 degrees following TKA. From a consecutive cohort of 3,058 mobile-bearing TKAs, 49 (1.6%) patients were diagnosed as having arthrofibrosis, of which 38 (86%) could be recruited for clinical assessment. Femoral rotation of a control group of 38 asymptomatic TKA patients matched for age, gender, and body mass index was also evaluated. The surgical epicondylar axis was compared with the posterior condylar axis for the femoral prosthesis. Femoral components in the arthrofibrosis group were significantly internally rotated by a mean of 4.7 degrees (SD 2.2 degrees , range 10 degrees internal to 1 degrees external). In the control group, the femoral component had a mean 0.3 degrees internal rotation (SD 2.3 degrees , range 4 degrees internal to 6 degrees external). Following mobile-bearing TKA, there is a significant correlation between internal femoral component rotation and chronic arthrofibrosis.

Shoulders of throwing athletes are highly stressed joints and likely to have more structural abnormalities seen on magnetic resonance imaging scans. Prevalence and type of structural abnormalities, especially abnormalities of the rotator cuff tendons and the superolateral humeral head, and correlation of magnetic resonance imaging findings with symptoms and clinical tests, are not well known. Throwing and nonthrowing (symptomatic and asymptomatic) shoulders of 30 fully competitive professional handball players and 20 dominant shoulders of randomly selected volunteers were evaluated for comparison clinically and with magnetic resonance imaging. An average of seven abnormal magnetic resonance imaging findings was observed in the throwing shoulders; more than in the nonthrowing and the control shoulders. Although 93% of the throwing shoulders had abnormal magnetic resonance imaging findings, only 37% were symptomatic. Partial rotator cuff tears and mainly superolateral osteochondral defects of the humeral head were identified as typical throwing lesions. Symptoms correlated poorly with abnormalities seen on magnetic resonance imaging scans and findings from clinical tests. This suggests that the evaluation of an athlete's throwing shoulder should be done very thoroughly and should not be based mainly on abnormalities seen on magnetic resonance imaging scans.

MR Arthrography of the Hip: Diagnostic Performance of a Dedicated Water-Excitation 3D Double-Echo Steady-State Sequence to Detect Cartilage LesionsPatrick R. Knuesel1 2, Christian W. A. Pfirrmann1, Hubert P. Noetzli3 4, Claudio Dora3, Marco Zanetti1, Juerg Hodler1, Bernd Kuehn5 and Marius R. Schmid1Audio Available | Share

Dialysis-related amyloidosis occurs secondarily to the deposition of beta(2)-microglobulin. Dialysis-related amyloidosis predominantly involves the osteoarticular system and is clinically manifested by erosive and destructive osteoarthropathies, destructive spondyloarthropathy, and carpal tunnel syndrome. This article illustrates the radiographic, sonographic, CT, and MRI findings of dialysis-related amyloid arthropathies.Dialysis-related amyloidosis is characterized by various imaging appearances. In evaluating amyloidosis, MRI provides considerably more information than that obtained from conventional radiographic, CT, and sonographic studies.

Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis. The goal of this study was to assess the frequency and distribution of abnormalities on whole body MR imaging in patients with suspected early ankylosing spondylitis and with active confirmed ankylosing spondylitis. Ten patients with suspected early ankylosing spondylitis and ten patients with confirmed ankylosing spondylitis were enrolled. On an 18-channel MR system, coronal and sagittal T1 weighted and STIR sequences were acquired covering the entire spine, sacrum, anterior chest wall, shoulder girdle, and pelvis. The total examination time was 30 minutes. In both groups inflammatory lesions of the lower thoracic spine were frequent (number of patients with suspected early/confirmed ankylosing spondylitis: 7/9). In confirmed ankylosing spondylitis the upper thoracic spine (3/6) and the lumbar spine (4/8) were more commonly involved. The inferior iliac quadrant of the sacroiliac joints was frequently altered in both groups (8/8). The superior iliac (2/5), inferior sacral (6/10) and superior sacral (3/6) quadrants were more frequently affected in confirmed ankylosing spondylitis. Abnormalities of the manubriosternal joint (2/4), the sternoclavicular joints (1/2) and hip joint effusion (4/3) were also seen. In both suspected early ankylosing spondylitis and confirmed ankylosing spondylitis, whole body MR examinations frequently demonstrate inflammatory lesions outside the sacroiliac joints. These lesions are similarly distributed but occur less frequently in suspected early compared to confirmed ankylosing spondylitis. Due to the small sample size in this pilot study these results need to be confirmed in larger studies with this emerging technique.

Rotator cuff repairs in patients aged older than 65 years are reported to have a high failure rate. Furthermore, asymptomatic cuff tearing is frequent in this age group, so the value of tendon repair has been questioned. Our aim was to review the results of cuff repair in these patients and to identify factors predicting outcome.In this study, 58 patients aged older than 65 years with reparable supraspinatus tears underwent primary open (22 patients) or arthroscopic (36 patients) repair. The leading symptom was pain despite nonoperative treatment for at least 6 months. Tendon healing was assessed on ultrasonography.Forty-four shoulders could be reviewed at a mean follow-up of 57 months (range, 24-112 months). Tendon healing was complete in 31 shoulders (70%). The mean Constant score (CS) improved from 49 points (range, 5-74 points) preoperatively to 78 points (range, 23-100 points) at follow-up (P < .05). The respective values for the relative CS were 64% (range, 7%-97%) and 95% (range, 33%-100%) (P < .05). The mean CS was better for healed repairs (82 points [range, 57-100 points]) than for nonhealed repairs (61 points [range, 23-88 points]) (P < .05). In 41 of 44 cases (93%), patients were satisfied or very satisfied with the operation. Though not statistically significant, dominance, cortisone injection, smoking, and tendon retraction appeared to favor nonhealing.Isolated supraspinatus tendon repairs in patients aged older than 65 years have a high healing potential and yield good clinical results with even better outcome if the repairs heal. Repair of symptomatic single-tendon rotator cuff tears in patients aged older than 65 years who do not respond to conservative treatment appears justified.

To evaluate the frequency of the supraacetabular fossa (SAF) (pseudodefect of acetabular cartilage) at magnetic resonance (MR) arthrography of the hip and to compare the MR findings with those from arthroscopy.All patients gave written permission for anonymized use of their medical data for scientific purposes before the imaging examination. The study was submitted to the institutional review board, and the need to obtain additional approval was waived. A medical student, a radiology fellow, and two senior radiologists reviewed 1002 consecutive MR arthrograms for the presence of an accessory bony fossa in the roof of the acetabulum, or SAF. SAF was classified into two types: type 1, which was filled with contrast material on MR arthrograms, and type 2, which was filled with cartilage. The width of the SAF was measured on coronal and sagittal MR images. MR arthrograms showing SAF were evaluated for subchondral reactions. Findings at MR arthrography were compared with those from arthroscopy in four hip joints with SAF type 1 and 13 with SAF type 2.Sixteen of the 1002 hip joints (1.6%; four female and 12 male patients; mean age, 20.1 years) had SAF type 1 (mean width, 5.2 × 4.5 mm). Eighty-nine hip joints (8.9%; 43 female and 46 male patients; mean age, 37.8 years) had SAF type 2 (mean width, 5.1 × 4.7 mm). No subchondral changes were found around the SAF. No cartilage defect was seen at the site of the SAF at arthroscopy.The high frequency of SAF on MR arthrograms (10.5%), the absence of subchondral reaction, and the absence of cartilage defects at arthroscopy indicate that the SAF of the acetabulum likely represents a variant.

Ankle ligament injuries are among the most common injuries in sports and recreational activities. Injuries of the medial collateral ligament or deltoid ligament complex account for ∼ 15% of ligamentous ankle trauma. They are usually associated with injuries of the lateral collateral ligaments and the tibiofibular syndesmosis, as well as malleolar fractures. The deltoid ligament complex consists of a superficial and a deep layer. The three main components of the superficial layer are the tibionavicular, tibiospring, and tibiocalcaneal ligaments. The deep layer is composed of the anterior and posterior tibiotalar ligaments; the latter is the strongest ligament of the whole complex. In approximately half of patients, injuries of the superficial layer are associated with a lesion of the posterior tibiotalar ligament (pTTL), whereas in contradistinction most injuries to the pTTL are associated with lesions of the superficial layer. The most common location of injuries to the superficial layer is at the tibial periosteal attachment with partial discontinuity, delamination, or a complete tear with or without lesions of the flexor retinaculum. Lesions of the pTTL are often midsubstance. In chronic lesions a distorted and thickened superficial layer at the tibial insertion with periosteal reaction and bony spurs is usually visible. The scarred pTTL shows loss of normal striation. In chronic stages of pTTL lesions, volume loss is typically seen. Associated periosteal spurs and intraligamentous ossicles are common. In late stages, tibiotalar valgus with osteoarthritic changes of the ankle will develop.

To determine the effect of magnetic resonance (MR) imaging results on diagnostic thinking and therapeutic decisions by orthopedic surgeons in cases of a possible Morton neuroma.Orthopedic surgeons completed a questionnaire before and after MR imaging for 54 feet in 49 patients thought to have Morton neuroma. Clinical diagnosis (Morton neuroma, differential diagnosis), location, diagnostic confidence, and therapeutic decisions were noted before and after MR imaging. The influence of the size of the neuroma on therapeutic decisions was analyzed. MR imaging diagnoses were compared with surgical results for 23 revised intermetatarsal spaces.After MR imaging, the clinical diagnosis of Morton neuroma was withdrawn in 15 of 54 (28%) feet. In 14 of 39 maintained diagnoses, the location or number of neuromas was changed after MR imaging. Confidence levels for Morton neuroma increased substantially after MR imaging. In 31 (57%) feet, a change in treatment plan resulted after MR imaging. Diameters of neuromas on MR images were significantly larger (P = .003) in surgically treated feet than in conservatively treated feet. MR imaging diagnoses were correct in all 23 revised intermetatarsal spaces.MR imaging has a major effect on diagnostic thinking and therapeutic decisions by orthopedic surgeons when Morton neuroma is suspected, especially because MR imaging helps in localization and size assessment of Morton neuromas.

The purpose of this study was to determine whether occult bony injuries or other characteristic MR abnormalities are frequent in patients suspected of having traumatic tears of the rotator cuff.MR arthrography of the shoulder was performed in 24 consecutive patients with suspected traumatic tears of the rotator cuff. MR findings were analyzed with regard to abnormalities of the supraspinatus, infraspinatus, and subscapularis tendons; and the humeral head. A comparison group of 24 consecutive patients with symptoms of nontraumatic tears of the rotator cuff was included in the investigation.Radiographically occult fractures of the greater tuberosity were found in nine (38%) of 24 patients with clinically suspected traumatic tears of the rotator cuff (seven of which occurred in patients <40 years old). Nine partial-thickness and five full-thickness supraspinatus tears were found in the trauma group. In the comparison group, the corresponding numbers were 13 and 10, respectively. Seven partial lesions of the cranial border of the subscapularis and six complete subscapularis tears (all six in patients >40 years old) were found in the trauma group (nine and one in the comparison group).Occult greater tuberosity fractures and complete subscapularis tears are commonly seen on MR images in patients suspected of having traumatic tears of the rotator cuff. Greater tuberosity fractures should be looked for specifically in patients younger than 40 years, and subscapularis tears should be looked for specifically in patients older than 40 years.

Abstract Our purpose was to evaluate the diagnostic efficacy of a gradient‐echo sequence optimized for cartilage imaging in patellar cartilage abnormalities and to compare it to a standard turbo‐spin‐echo sequence. Fifty‐eight consecutive patients who underwent, within 3 months both MRI and arthroscopy or surgery, were included in the investigation. Two radiologists specializing in musculoskeletal imaging independently assessed axial three‐dimensional double‐echo steady state (3D‐DESS) gradient‐echo images and sagittal proton‐ and T2‐weighted turbo‐spin‐echo images with regard to retropatellar cartilage abnormalities. Possible findings were: 0: normal, 1: cartilage softening, and 2: lesion of the articular surface. Inter‐ and intraobserver variability was assessed. For cartilage softening, the axial 3D‐DESS sequence had a sensitivity of 73%, a specifity of 75%, and an accuracy of 70%. The corresponding results for the sagittal turbo‐spin‐echo sequence were 53%, 65%, and 62%. For surface lesions, the results for the 3D‐DESS sequence were 43%, 92%, and 83% and for the turbo‐spin‐echo sequence were 60%, 92%, and 86%. Intra‐ and interobserver agreement was moderate ( k = 0.59 and 0.45 [DESS], 0.6 and 0.46 [turbo ‐spin‐echo]). We conclude that the 3D‐DESS sequence is moderately accurate in detecting patellar cartilage abnormalities. Compared with the sagittal turbo‐spin‐echo sequence, the axial 3D‐DESS sequence is superior in diagnosing cartilage softening but not surface lesions.

To assess the effect of prone, supine, and upright weight-bearing body positions on visibility, position, shape, and size of Morton neuroma during magnetic resonance (MR) imaging.Eighteen patients with 20 Morton neuromas underwent MR imaging of the forefoot in prone (plantar flexion of the foot), supine (dorsiflexion of the foot), and upright weight-bearing positions. Visibility (3 = good, 2 = moderate, 1 = poor), position relative to the metatarsal bone, shape, and transverse diameter of Morton neuroma were assessed on transverse T1-weighted MR images. Associations between different body positions and variables of interest were calculated with Wilcoxon signed rank test, chi2 test, and paired Student t test.In the prone position, visibility of all 20 Morton neuromas was rated with a score of 3; visibility in the supine and weight-bearing positions was inferior (mean score, 2.4). All 20 (100%) Morton neuromas changed their position relative to the metatarsal bone between prone and supine and between prone and weight-bearing positions. When compared with the prone position, there was a difference in the shape of all 20 Morton neuromas in the weight-bearing position (P <.001). Between prone (mean transverse diameter of Morton neuroma, 8 mm) and supine (mean transverse diameter of Morton neuroma, 6 mm) positions, the transverse diameter of Morton neuroma significantly decreased by 2 mm (P =.03); between prone and weight-bearing positions, the decrease of the mean transverse diameter was also significant (difference, 2 mm; P =.03).Morton neuroma appears significantly different during MR imaging in prone, supine, or weight-bearing positions. The transverse diameter of Morton neuroma is significantly larger on images obtained in the prone position than it is on images obtained in the supine and upright weight-bearing positions. Visibility of Morton neuroma is best on MR images obtained in the prone position.

Magnetic resonance (MR) imaging of Morton neuromas is highly accurate. Morton neuromas are more conspicuous when the patient is prone positioned and the foot is plantar flexed than in the supine position with the toes pointing upward. MR imaging of Morton neuromas has a large influence on the diagnostic thinking and treatment plan of orthopedic foot surgeons. The most common differential diagnoses include intermetatarsal bursitis, stress fractures, and stress reactions. Some diagnoses (nodules associated with rheumatoid arthritis, synovial cyst, soft tissue chondroma, and plantar fibromatosis) are rare and can be diagnosed with histologic correlation only.

To retrospectively evaluate the magnetic resonance (MR) imaging findings of anterior tibial tendon (ATT) abnormalities.Institutional review board approval was not necessary for review of patient images and was granted for examination of the volunteers; informed consent was obtained. MR imaging findings in 28 consecutive patients (20 women, eight men; mean age, 63.2 years) clinically suspected of having an ATT abnormality were compared with those in an age- and sex-matched control group of 28 asymptomatic volunteers (20 women, eight men; mean age, 62.9 years). Surgical correlation was available for 11 patients. The short-axis diameter of the ATT and the longitudinal extent of signal intensity abnormalities were measured (Mann-Whitney U test). Signal intensity abnormalities of the ATT and irregularities of the underlying tarsal bones were analyzed in consensus by two blinded radiologists (chi2 test).In the symptomatic group, three cases of tendinosis and 13 partial and 12 complete ATT tears were diagnosed. In 11 cases (one case of tendinosis and two cases of partial and eight cases of complete ATT tear), surgical correlation was available and the MR imaging diagnosis was confirmed. In the asymptomatic group, four cases of tendinosis of the ATT were seen. The ATT diameter was significantly thicker in symptomatic patients at 1 cm (5.1 vs 3.1 mm in control group, P < .001), 3 cm (5.8 vs 3.4 mm, P < .001), and 6 cm (5.4 vs 4.3 mm, P = .006) proximal to the distal point of insertion. Most ATT abnormalities (in 23 [82%] of 28 patients) were located within the first 3 cm proximal to the insertion. Signal intensity abnormalities were seen in the anterior portion of the ATT in two (7%) of the 28 symptomatic patients and in the posterior portion in 11 (39%); diffuse involvement was seen in 15 (54%). Bone spurs on the navicular surface (nine [32%] patients vs no [0%] control subjects, P = .001), a ridged shape of the medial surface of the medial cuneiform bone (13 [46%] vs one [4%], P < .001), and osteophyte formation at the first tarsometasarsal joint (eight [29%] vs two [7%], P = .036) were significantly more common in the symptomatic patient group.Characteristic findings of ATT abnormalities include tendon thickening (> or =5 mm) and diffuse or posterior signal intensity abnormalities of the tendon within 3 cm from the distal point of insertion.

MR imaging of the shoulder is widely used for assessment of impingement and instability-related clinical conditions. The following review article demonstrates the normal anatomy, variations and classical pitfalls. In addition to classical pitfalls (sublabral hole, sublabral recess, Buford complex) the authors focus on a number of normal, bony, cartilaginous, ligamentous and tendinous structures that can simulate disease at the shoulder. In addition, ways to distinguish these pitfalls from true shoulder abnormalities are shown.

To assess the association between trochanteric surface irregularities seen on conventional radiographs and magnetic resonance (MR) evidence of abductor tendon abnormalities.A total of 150 consecutive patients were evaluated in this retrospective study (age range, 21-88 years; mean age, 58.7 years ± 16.1 [standard deviation]; 57 men, 93 women). Because patients' rights are protected by a procedure in which they are asked to provide general approval for their records and images to be reviewed for scientific purposes, specific approval by the institutional review board was not required. Two readers independently analyzed conventional radiographs and MR images of the hip. Trochanteric surface was graded on conventional radiographs as normal, osseous irregularities extending 1-2 mm, or osseous irregularities extending more than 2 mm. On MR images, the gluteus minimus and gluteus medius tendons were classified as normal or as having tendinopathy or a partial- or full-thickness tear. Logistic regression analysis and the Fisher exact test were used for statistical analysis. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive likelihood ratio were calculated. To assess interobserver agreement, a κ statistic was used.The positive predictive value of surface irregularities larger than 2 mm for MR tendinopathy or a partial- or full-thickness tear was 90% (37 of 41 patients). The sensitivity of radiographic changes was 40%; the specificity, 94%; the accuracy, 61%; the negative predictive value, 49%; and the positive likelihood ratio, 5.8. Interobserver agreement for detection of trochanteric surface irregularities on conventional radiographs ranged from 0.28 to 0.76.Pronounced (>2 mm) surface irregularities of the greater trochanter on conventional radiographs were associated with abductor tendon MR abnormalities.

To compare the accuracy of dynamic gadolinium-enhanced magnetic resonance (MR) imaging with that of standard MR imaging for assessing the viability of the proximal pole of the scaphoid in patients with nonunion.The study protocol was submitted to the institutional review board, and the need to obtain additional approval was waived for this retrospective study. Twenty-eight patients (mean age ± standard deviation, 24.3 years ± 6.4) with nonunion of a scaphoid fracture underwent dynamic gadolinium-enhanced MR imaging of the wrist 28 days ± 19 before surgery. Dynamic gadolinium-enhanced MR imaging consisted of acquisition of 40 consecutive coronal T1-weighted images over 1 minute. Two readers retrospectively evaluated MR images obtained with a standard protocol and rated the viability of the proximal scaphoid pole. The steepest upslope of gadolinium uptake was calculated in a region of interest placed in the proximal scaphoid pole by a third reader. Receiver operating characteristic curves were calculated, and the areas under the receiver operating characteristic curve (A(z) values) were compared. Diagnostic performance in determining scaphoid viability was calculated for readers 1 and 2. Histologic findings in 11 patients and surgical findings in all patients served as the standard of reference.The sensitivity, specificity, and accuracy of standard MR imaging in the detection of scaphoid necrosis were 54%, 93%, and 75%, respectively, for reader 1 and 62%, 93%, and 78% for reader 2. Interreader reliability was excellent (κ = 0.92). The A(z) was 0.82 for reader 1 and 0.87 for reader 2. The diagnostic performance of dynamic gadolinium-enhanced MR imaging, determined with the steepest upslope value, was inferior to that of standard MR imaging, with an A(z) of 0.57. Findings at histologic examination (viable bone, necrotic bone, callus formation) did not correlate with those at dynamic gadolinium-enhanced MR imaging.Because the diagnostic performance of dynamic gadolinium-enhanced MR imaging in the evaluation of scaphoid viability was inferior to that of a standard MR imaging protocol, dynamic acquisition may not be needed in patients with nonunion of scaphoid fractures.

The purpose of this article is to evaluate the use of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for artifact reduction and overall image quality improvement for intermediate-weighted and T2-weighted MRI of the shoulder.One hundred eleven patients undergoing MR arthrography of the shoulder were included. A coronal oblique intermediate-weighted turbo spin-echo (TSE) sequence with fat suppression and a sagittal oblique T2-weighted TSE sequence with fat suppression were obtained without (standard) and with the PROPELLER technique. Scanning time increased from 3 minutes 17 seconds to 4 minutes 17 seconds (coronal oblique plane) and from 2 minutes 52 seconds to 4 minutes 10 seconds (sagittal oblique) using PROPELLER. Two radiologists graded image artifacts, overall image quality, and delineation of several anatomic structures on a 5-point scale (5, no artifact, optimal diagnostic quality; and 1, severe artifacts, diagnostically not usable). The Wilcoxon signed rank test was used to compare the data of the standard and PROPELLER images.Motion artifacts were significantly reduced in PROPELLER images (p < 0.001). Observer 1 rated motion artifacts with diagnostic impairment in one patient on coronal oblique PROPELLER images compared with 33 patients on standard images. Ratings for the sequences with PROPELLER were significantly better for overall image quality (p < 0.001). Observer 1 noted an overall image quality with diagnostic impairment in nine patients on sagittal oblique PROPELLER images compared with 23 patients on standard MRI.The PROPELLER technique for MRI of the shoulder reduces the number of sequences with diagnostic impairment as a result of motion artifacts and increases image quality compared with standard TSE sequences. PROPELLER sequences increase the acquisition time.

The purpose of this agreement was to establish evidence-based consensus statements on imaging of scapholunate joint (SLJ) instability by an expert group using the Delphi technique.Nineteen hand surgeons developed a preliminary list of questions on SLJ instability. Radiologists created statements based on the literature and the authors' clinical experience. Questions and statements were revised during three iterative Delphi rounds. Delphi panellists consisted of twenty-seven musculoskeletal radiologists. The panellists scored their degree of agreement to each statement on an eleven-item numeric scale. Scores of '0', '5' and '10' reflected complete disagreement, indeterminate agreement and complete agreement, respectively. Group consensus was defined as a score of '8' or higher for 80% or more of the panellists.Ten of fifteen statements achieved group consensus in the second Delphi round. The remaining five statements achieved group consensus in the third Delphi round. It was agreed that dorsopalmar and lateral radiographs should be acquired as routine imaging work-up in patients with suspected SLJ instability. Radiographic stress views and dynamic fluoroscopy allow accurate diagnosis of dynamic SLJ instability. MR arthrography and CT arthrography are accurate for detecting scapholunate interosseous ligament tears and articular cartilage defects. Ultrasonography and MRI can delineate most extrinsic carpal ligaments, although validated scientific evidence on accurate differentiation between partially or completely torn or incompetent ligaments is not available.Delphi-based agreements suggest that standardized radiographs, radiographic stress views, dynamic fluoroscopy, MR arthrography and CT arthrography are the most useful and accurate imaging techniques for the work-up of SLJ instability.• Dorsopalmar and lateral wrist radiographs remain the basic imaging modality for routine imaging work-up in patients with suspected scapholunate joint instability. • Radiographic stress views and dynamic fluoroscopy of the wrist allow accurate diagnosis of dynamic scapholunate joint instability. • Wrist MR arthrography and CT arthrography are accurate for determination of scapholunate interosseous ligament tears and cartilage defects.

To characterize triangular fibrocartilage (TFC) defects in symptomatic and contralateral asymptomatic wrists.Communicating and noncommunicating defects of the TFC were depicted on bilateral wrist arthrograms in 56 patients with unilateral wrist pain and without associated lesions of the scapholunate or lunotriquetral ligaments. The exact location of each TFC lesion was noted.Communicating defects were noted in 36 (64%) of 56 symptomatic and in 26 (46%) of 56 asymptomatic wrists. Twenty-five (69%) of 36 communicating defects were bilateral. Except for one defect in each group of symptomatic and asymptomatic wrists, all communicating defects were noted radially. Noncommunicating defects were noted in 28 (50%) of 56 symptomatic wrists and in 15 (27%) of 56 asymptomatic wrists. Eleven (39%) of 28 noncommunicating defects were bilateral. On the symptomatic side, 28 of 36 noncommunicating defects (including eight multiple defects) were located proximally at the ulnar side. On the asymptomatic side, 11 of 17 noncommunicating defects (including two multiple defects) were at or near the ulna.Noncommunicating TFC defects, which typically are located on the proximal side of the TFC near its ulnar attachment, have a more reliable association with symptomatic wrists than do communicating defects. Radial-sided communicating defects described in the literature (Palmer type 1A and 1D) as posttraumatic commonly are seen bilaterally and in asymptomatic wrists.

To assess whether MR abnormalities of the intervertebral disks and adjacent bone marrow can predict segmental instability of the lumbar spine as diagnosed on functional radiographs.A consecutive review was made of 60 patients examined with MR imaging and with lateral flexion and extension views of the lumbar spine. Sagittal T1- and T2-weighted images were evaluated blindly with regard to abnormalities of the intervertebral disk and the adjacent bone marrow. Segmental instability was diagnosed when a.p. translation of 3 mm or more was present on the functional radiographs. Moreover, the presence of osteophytes was evaluated on lateral standard radiographs.Of a total of 300 segments, 32 (10.7%) were unstable. Anular tears were the most relevant MR finding. Their sensitivity, specificity, and positive and negative predictive values for segmental instability were 18.8%, 97.0%, 42.9% and 90.9%. The corresponding values for traction osteophytes were 12.5%, 98.1%, 44.4% and 90.4%. Abnormalities of bone marrow were not significantly related to segmental instability (p=0.35).Functional radiographs should be considered in patients with anular tears or traction osteophytes. No correlation was found between segmental instability and abnormalities of bone marrow adjacent to the endplates.

To evaluate the three standard orthogonal imaging planes and a paracoronal imaging plane for anterior cruciate ligament (ACL) tears.Ninety patients (91 knees; 29 F and 61 M) aged between 15 and 84 years (mean 36.9 +/- 16.4 years) underwent magnetic resonance imaging (MRI) of the knee prior to arthroscopy. At surgery, 32 knees had an intact ACL, 4 a partial tear, and 55 a complete ACL tear. In all patients, axial, sagittal, coronal, and paracoronal T2-weighted turbo-SE images were acquired. The ACL was classified as intact, partially, or completely torn. Partial and complete tears were combined for statistical evaluation.Partial ACL tears (four cases) were not correctly diagnosed at MRI except in one knee by one observer on coronal images. Sensitivity in detecting ACL tears was 95%/63% (reader1/reader2) in the axial, 93%/95% in the sagittal, 93%/86% in the coronal, and 100%/93% in the paracoronal plane. Specificity was 75%/81% in the axial, 72%/81% in the sagittal, 78%/94% in the coronal, and 78%/88% in the paracoronal plane.ACL tears can be diagnosed accurately with each of the standard orthogonal planes. Based on reader confidence and interobserver agreement paracoronal images may be useful in equivocal cases.

To evaluate the clinical outcome of edema-like bone marrow abnormalities seen on magnetic resonance (MR) images of the foot when their cause is unknown.The clinical outcome of 31 patients (15 female patients, 16 male patients; mean age, 51; range, 10-79 years) with edema-like bone marrow abnormalities on MR images of the foot was determined. The relevance of three different edema patterns was compared: (a) exclusively ill-defined edema-like zones, (b) edema-like zones plus well-defined necrosis-like zones, and (c) edema-like zones plus linear structures indicating possible fractures. The different edema patterns were compared with persistence of pain.Fifty-four percent of all patients had pain persisting after 1 year, as calculated with the Kaplan-Meier method. The duration of pain in the various subgroups varied significantly (P =.049, log-rank test). The subgroup of patients with a well-defined necrosis-like zone had substantially longer-lasting pain than those with edema-like abnormalities only (n = 16) (P =.065). Only one of seven patients with a well-defined necrosis-like zone (n = 7) was pain free after 1 year. Conversely, patients with possible stress fracture (n = 8) had shorter pain compared with those with edema-like abnormalities only (P =.036); six of eight patients were pain free after 1 year.Edema-like bone marrow abnormalities of the foot predict long-lasting pain. Analysis of the image patterns of such abnormalities allows prediction of the clinical outcome to a certain degree.

Our objective was to evaluate the predictive value of various MRI findings in the acromioclavicular joint for pain relief after intraarticular injection.The acromioclavicular joint of 50 patients (20 women, 30 men; mean age, 51 years; range, 25-75 years) was evaluated on MRIs of the shoulder. Osteophytes, subchondral cysts and irregularities, bone marrow edema, joint effusion, and joint capsule hypertrophy were assessed by two musculoskeletal radiologists in consensus. Local anesthetics were injected into the acromioclavicular joint with fluoroscopic guidance. Patients graded pain relief on a visual analogue scale (0-100%) after 15 min. The relationship between pain relief and MRI findings was assessed with the Mann-Whitney U test. Pain relief equal to or greater than 70% was rated as a positive response to the injection. This cutoff value was used to calculate sensitivity, specificity, accuracy, and predictive values of the various MRI findings in determining which acromioclavicular joints were responsive to joint injections.Mean pain relief after injection was 38%. Pain relief was significantly related to capsular hypertrophy (p = 0.007) and was equal to or greater than 70% in 11 patients. The sensitivity in diagnosing a successful injection (range, 9-82%) was highest for caudal osteophytes (82%) and capsular hypertrophy (73%). The specificity (range, 51-97%) was highest for subchondral cysts (97%), subchondral bone marrow edema (95%), and joint effusion (92%).Pain relief after intraarticular injection is significantly related to capsular hypertrophy diagnosed on MRI. MRI findings have a reasonable sensitivity and a high specificity in predicting relevant short-term pain relief after intraarticular injection.

PURPOSE: To retrospectively evaluate if the degree of disk degeneration and disk herniation volume at magnetic resonance (MR) imaging are risk factors for recurrent disk herniation. MATERIALS AND METHODS: The institutional review board permits such retrospective studies, and individual informed consent was not required. MR imaging findings obtained before initial diskectomy in 30 patients (mean age, 42.8 years; 10 women, 20 men) with recurrent disk herniation (study group) and 30 patients (mean age, 42.2 years; nine women, 21 men) without recurrence for at least 2 years after surgery (control group) were compared. Disk degeneration was assessed on T2-weighted sagittal MR images with a five-point grading system (grade I indicated no degeneration; grade II, horizontal hypointense bands within disk; grade III, inhomogeneous disk with intermediate signal intensity; grade IV, no distinction between inner and outer parts of disk; and grade V, collapsed hypointense disk). Disk herniation was classified as representing protrusion, extrusion, or sequestration. The volume of both the affected intervertebral disk and the herniated disk material was measured. Qualitative and quantitative analyses were performed by two readers. The χ2 test was used for comparison of categorical variables. For comparison of disk degeneration and volumes between patients with and those without recurrence, a paired two-tailed t test was used. Odds ratios based on the extent of disk degeneration were calculated for the entire sample. RESULTS: Advanced disk degeneration (grades IV and V) was significantly less frequent in the study group than in the control group (P < .006). The risk of recurrent disk herniation decreased by a factor of 3.4 for each increase in grade of disk degeneration (odds ratio: 3.58; 95% confidence interval: 1.3, 9.6; P = .011). Mean disk herniation volume as a percentage of intervertebral disk volume was 10.59% ± 3.41 in the study group and 11.56% ± 3.84 in the control group. This difference was not significant (P = .31). CONCLUSION: Minor disk degeneration but not herniation volume represents a risk factor for the recurrence of disk herniation after diskectomy. © RSNA, 2005

To retrospectively evaluate plantar fat pad (PFP) signal intensity alterations in magnetic resonance (MR) imaging studies of asymptomatic volunteers and to compare PFP alterations with histopathologic findings in cadavers and patients.After appropriate institutional review board approval and any required informed consent were obtained, MR imaging studies of 70 asymptomatic volunteers (35 women, 35 men; mean age, 45 years; range, 21-69 years) obtained for another investigation were retrospectively analyzed by two musculoskeletal radiologists in consensus. The location, signal intensity, margin, extent, and size of PFP alterations were determined. MR imaging-histopathologic comparison was performed in six cadaveric feet and six feet of symptomatic patients (one woman, five men; mean age, 43 years; range, 31-60 years). For volunteers, the relationship between PFP alterations and Morton neuroma, age, and sex was analyzed by using the Fisher exact test, Spearman rank correlation, and the Wilcoxon rank sum test, respectively. Bonferroni correction was applied, and P < .01 was considered to indicate a significant difference.Fifty-nine (84%) volunteers had PFP signal intensity alterations. Forty-nine (70%), six (9%), one (1%), four (6%), and 43 (61%) volunteers had alterations beneath the first, second, third, fourth, and fifth metatarsal heads, respectively. Ninety-four (91%) of 103 signal intensity alterations were in the form of hypointensity on T2-weighted images. Blurred margins were present in 90 (87%) alterations. Ninety percent of all PFP alterations in asymptomatic volunteers were 14 mm or smaller. The relationship between PFP alterations and Morton neuroma, age, and sex was not statistically significant. In cadaveric forefeet, PFP alterations corresponded histopathologically to a variable amount of fibrosis. In nine PFP alterations, development of fluid-containing spaces resembling bursae was present. Among the six patients with PFP alterations, histopathologic examination revealed fibrosis and adventitious bursae in two, fibrosis with inflammation in three, and a soft-tissue chondroma in one.PFP signal intensity alterations are commonly seen in asymptomatic volunteers under the first and fifth metatarsal heads. At histologic examination, PFP signal intensity alterations correspond most commonly to fibrosis and adventitious bursae.

Protection against intracellular pathogens or tumor antigens requires T-cell mediated responses. Recently, it has become apparent that protection against disease correlates with T cells of the central memory type in many instances. Here, we analyze current data to distill a set of rules for the induction and maintenance of central memory T-cell responses. Recent studies show that T-cell help and the lack of overt inflammation at the time of priming are prerequisite for the induction, maintenance and expansion of memory T cells. Central to our hypothesis is that, in addition to these factors, successful vaccination in the immunologically inexperienced individual should be based on low antigen dose, to decelerate replicative senescence in responding cells and favor lineage differentiation of central memory T cells. In the immunologically experienced individual, it will be necessary, in addition, to abate the antigen load in plasma before vaccination. These guiding principles might help to raise improved protective T-cell responses by vaccination in humans. Protection against intracellular pathogens or tumor antigens requires T-cell mediated responses. Recently, it has become apparent that protection against disease correlates with T cells of the central memory type in many instances. Here, we analyze current data to distill a set of rules for the induction and maintenance of central memory T-cell responses. Recent studies show that T-cell help and the lack of overt inflammation at the time of priming are prerequisite for the induction, maintenance and expansion of memory T cells. Central to our hypothesis is that, in addition to these factors, successful vaccination in the immunologically inexperienced individual should be based on low antigen dose, to decelerate replicative senescence in responding cells and favor lineage differentiation of central memory T cells. In the immunologically experienced individual, it will be necessary, in addition, to abate the antigen load in plasma before vaccination. These guiding principles might help to raise improved protective T-cell responses by vaccination in humans.

To develop and assess a technique to evaluate cam type femoroacetabular impingement (FAI) using ultrasound (US). Fifty patients (24 women, 26 men) were included (mean age: 39.1 years; age range: 16–59). US images of the anterior and anterosuperior contour of the femoral neck were obtained and analysed in 50 patients. Non-spherical shape of the head-neck junction (cam deformity), bony protuberances at the femoral neck, shape of the femoral neck (waist deficiency) and alpha angle were assessed. Magnetic resonance (MR) arthrography served as the standard of reference. Diagnostic performance and receiver operating characteristics (ROC) curves were calculated. Based on MR arthrography 28 patients had cam-type FAI. On US, an anterosuperior cam deformity was seen in 40/44 patients (Reader 1/Reader 2; sensitivity 93%/89%, specificity 36%/14%). A bony protuberance anterosuperiorly in 23/13 patients (sensitivity 71%/32%, specificity 86%/82%) and an anterosuperior waist deficiency in 19/35 patients (sensitivity 25%/54%, specificity 100%/54%). Sensitivity and specificity of the other criteria were lower than 70% (average of Reader 1 & 2). A technique to evaluate cam type FAI using US is presented. The detection of an anterosuperior cam deformity is sensitive, and presence of an anterosuperior bony protuberance is specific for cam FAI. Alpha angle measurements are not helpful in establishing the diagnosis.

Early postoperative MRI after spinal surgery is difficult to interpret because of confounding postoperative mass effects and frequent occurrence of epidural hematomas. Purpose of this prospective study is to evaluate prevalence, extent and significance of hematoma in the first postoperative week in asymptomatic patients after decompression for lumbar stenosis and to determine the degree of clinically significant dura compression by comparing with the patients with postoperative symptoms. MRI was performed in 30 asymptomatic patients (47 levels) in the first week after lumbar spine decompression for degenerative stenosis. Eleven patients requiring surgical revision (16 levels) for symptomatic early postoperative hematoma were used for comparison. In both groups the cross-sectional area of the maximum dural compression (bony stenosis and dural sac expansion) was measured preoperatively and postoperatively by an experienced radiologist. Epidural hematoma was seen in 42.5% in asymptomatic patients (20/47 levels). The median area of postoperative hematoma at the operated level was 176 mm(2) in asymptomatic patients and 365 mm(2) in symptomatic patients. The median cross-sectional area of the dural sac at the operated level was 128.5 and 0 mm(2) in asymptomatic and symptomatic patients, respectively, at the site of maximal compression. In the symptomatic group 75% of the patients had a maximal postoperative dural sac area of 58.5 mm(2) or less, whereas in the asymptomatic group 75% of patients with epidural hematoma had an area of 75 mm(2) or more. The size of hematoma and the degree of dural sac compression were significantly larger in patients with symptoms needing surgical revision. Dural sac area of less than 75 mm(2) in early postoperative MRI was found to be the threshold for clinical significance.

To evaluate the therapeutic impact of [18F]fluoride positron-emission tomography/computed tomography ([18F]fluoride PET/CT) imaging on patients with unclear foot pain. Twenty-eight patients were prospectively included in this study. Therapeutic management was defined by two experienced dedicated foot surgeons before and after [18F]fluoride PET/CT imaging. Twenty-six patients underwent cross-sectional imaging [CT, magnetic resonance (MR)] prior to PET/CT. A retrospective analysis of the magnetic resonance imaging (MRI) diagnoses was performed when a therapy change occurred after PET/CT imaging. In 13/28 (46%) patients therapeutic management was changed due to PET/CT results. Management changes occurred in patients with the following diagnoses: os trigonum syndrome; sinus tarsi syndrome; os tibiale externum syndrome; osteoarthritis of several joints; non-consolidated fragments; calcaneo-navicular coalition; plantar fasciitis; insertional tendinopathy; suggestion of periostitis; neoarticulations between metatarsal bones. Os trigonum, os tibiale externum, subtalar osteoarthritis and plantar fasciitis were only seen to be active on PET/CT images but not on MR images. [18F]fluoride PET/CT has a substantial therapeutic impact on management in patients with unclear foot pain.

This document presents an interim framework in which the coupling structure of a Higgs-like particle can be studied. After discussing different options and approximations, recommendations on specific benchmark parametrizations to be used to fit the data are given.

The objective of this study was to investigate the clinical effectiveness of nerve root blocks (i.e., periradicular injection of bupivacaine and triamcinolone) for lumbar monoradiculopathy in patients with a mild neurological deficit. We have retrospectively analysed 30 patients (29-82 years) with a minor sensory/motor deficit and an unequivocal MRI finding (20 disc herniations, 10 foraminal stenoses) treated with a selective nerve root block. Based on the clinical and imaging findings, surgery (decompression of the nerve root) was justifiable in all cases. Twenty-six patients (87%) had rapid (1-4 days) and substantial regression of pain, five required a repeat injection. 60% of the patients with disc herniation or foraminal stenosis had permanent resolution of pain, so that an operation was avoided over an average of 16 months (6-23 months) follow-up. Nerve root blocks are very effective in the non-operative treatment of minor monoradiculopathy and should be recommended as the initial treatment of choice for this condition.

The purpose of this investigation is to compare a fat-suppressed T2-weighted fast spin-echo (FSE) sequence in bone marrow abnormalities with an FSE STIR sequence that recently has become commercially available.Fast spin-echo images (repetition time [TR], 3500-5000 mseconds; echo time [TE], 96-114 mseconds) and FSE STIR images (TR, 3000-5000 mseconds; TE, 32-40 mseconds; inversion time [TI], 140-150 mseconds) were compared quantitatively and qualitatively calculating signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), and lesion conspicuity and using a qualitative scoring system.Signal-to-noise ratio (mean +/- standard deviation) was 36.4 +/- 19.3 for the FSE and 29.0 +/- 15.9 for the FSE STIR images (P = .002). Contrast-to-noise ratio (mean +/- standard deviation) was 18.7 +/- 14.3 for the FSE and 20.3 +/- 16.0 for the FSE STIR images (P = .45). Lesion conspicuity (mean +/- standard deviation) was 1.7 +/- 1.5 for the FSE and 3.5 +/- 4.0 for the FSE STIR images (P = .025). The most important difference in the qualitative evaluation related to the better signal homogeneity on the FSE STIR images.Fast spin-echo STIR images may be preferable to FSE images with fat suppression due to better image homogeneity and lesion conspicuity.

To assess patient discomfort during (a) intraarticular contrast material injection (arthrography) and (b) magnetic resonance (MR) imaging in patients referred for MR arthrography of the shoulder and to compare the relative discomfort associated with each part of the examination.With use of a visual analogue scale (VAS) and relative ratings, 202 consecutive patients referred for MR arthrography of the shoulder rated the expected discomfort and that actually experienced during both arthrography and MR imaging. The Student t test was used for statistical analysis.The average VAS score (0 = "did not feel anything," 100 = "unbearable") was 16.1 +/- 16.4 (SD) for arthrography and 20.2 +/- 25.0 for MR imaging. This difference was statistically significant (P =.036, paired t test). The discomfort experienced during arthrography was as expected in 90 (44.6%) patients, less than expected in 110 (54.4%), and worse than expected in two (1.0%). MR imaging-related discomfort was as expected in 114 (56.4%) patients, less than expected in 66 (32.7%), and worse in 22 (10.9%). Arthrography was rated worse than MR imaging by 53 (26.2%) patients, equal to MR imaging by 69 (34.2%), and less uncomfortable than MR imaging by 80 (39.6%).Arthrography-related discomfort was well tolerated, often less severe than anticipated, and rated less severe than MR imaging-related discomfort.

To examine whether magnetic resonance (MR) imaging findings of the cervical spine can predict pain relief after selective computed tomography (CT)-guided nerve root block and thus assist in the appropriate selection of patients who are suitable for this procedure.Sixty consecutive patients with cervical radicular pain were examined with MR imaging and then treated with CT-guided cervical nerve root blocks (CNRBs). Various MR imaging findings were assessed and compared in terms of associated pain relief after CNRB. Pain relief was graded (0%-100%) by using a visual analogue scale (VAS). The relationship between MR imaging findings and level of pain relief was tested by using Mann-Whitney U and Kruskal-Wallis tests.The mean percentage of pain reduction at VAS grading was 46%. There was a significant relationship between pain relief level and both location of disk herniation (mean pain reductions of 41% at median or mediolateral locations and 64% at foraminal locations, P =.034) and location of nerve root compromise (mean pain reductions of 19% at intraspinal, 45% at foraminal entrance, and 58% at foraminal locations; P =.019). There was an inverse relationship between pain relief level and absence or presence of spinal canal stenosis (mean pain reductions of 29% when stenosis present and 53% when stenosis absent, P =.013). Other parameters were not significantly related to pain relief.MR imaging of the cervical spine assists in the appropriate selection of patients suitable for CNRB. Patients with foraminal disk herniation, foraminal nerve root compromise, and no spinal canal stenosis appear to have the greatest pain relief after this procedure.