Carol R. Archer

Twenty patients with basilar artery occlusion and three patients with bilateral vertebral artery occlusions have been studied. The clinical data at the time of the ictus and the long-term follow-up data have been correlated with the site and extent of the basilar artery occlusion and the type of collateral flow. Patients with hypertension and with coma at the outset have a grave prognosis. The presence of surface collateral flow may not indicate adequate perfusion of the paramedian penetrating branches of the basilar artery or the thalamoperforating branches of the posterior communicating or posterior cerebral arteries. It is these vessels which supply the territory regulating the level of consciousness and containing some of the control mechanisms for respiratory function.

The larynx is separated into compartments bounded by connective tissue membranes and cartilages. The membranes and cartilages affect the localization and spread of cancer for a while, but invasion eventually occurs. Histological study of the cartilages in the earliest stages of invasion shows cancer cells growing between the collagen bundles where the connective tissue membranes attach to the cartilages. At these points, the collagen bundles pass obliquely through the perichondrium to anchor into the cartilage and bone like Sharpey's fibers. As the cancer cells multiply, they separate the collagen bundles, forming linear passageways through the perichondrum. This appears to be the mechanism for cartilage invasion. Thus the sites of attachment of the strongest membranes are also the most frequent sites of invasion, i.e., the anterior commissure tendon and the cricothyroid membrane.

Ossification of adult laryngeal cartilages was studied using cross sections cut in planes parallel to those used in computed tomography (CT). The percentage of ossification of surfaces of thyroid laminae was calculated and marked variations were found. There was no correlation between ossification and age (all subjects were 50 years or older). Generally, laryngeal cartilages of men were ossified to a greater extent than those of women. Some male cartilages were only slightly ossified, however, while some female cartilages were nearly completely ossified. Inner and outer surfaces of thyroid laminae differed by as much as 35% in some cases. Left and right laminae showed even greater differences, indicating that symmetry of ossification is not the rule. Ossification of arytenoid and cricoid cartilages also varies. This study reveals that there is no reliable pattern of ossification of laryngeal cartilage that would be of use the radiologist in evaluating CT scans for invasion of cartilage by cancer.

We present a patient in whom dysphasia followed suddenly upon an apparently discrete thalamic infarct proven by computed tomography (CT). Detailed psychometric data of the patient's speech and memory disorder obtained during the acute and chronic stages were correlated with the evaluation of a focal thalamic lesion as demonstrated by serial CT. The findings and deductions drawn from selective reports in the literature form the basis of this presentation.

Computed tomography of the larynx was performed in 21 patients and 3 anatomic specimens for evaluation of laryngeal cancer. Special attention was directed to the appearance of the laryngeal cartilages in both the normal and abnormal examinations in order to establish criteria for cancerous invasion. The problem presented by the normal nonuniformity of density of the cartilages is discussed in detail.

The normal anatomy of the larynx as displayed on computed tomography is illustrated. Pathological alterations in patients with carcinoma of the larynx are depicted and discussed. Computed tomography (CT) is recommended as the initial radiological procedure when additional diagnostic information is required to supplement the findings of laryngoscopy. CT provides information regarding deep penetration of tumor, including cartilaginous invasion, and about the inferior extension of neoplasm, including the subglottic area. This knowledge helps to determine whether conservative surgery as opposed to total laryngectomy is possible.

A study of the findings on cistemograms and computerized transaxial tomography (CTT) of 44 patients showed good correlation between the two tests. Patients with a cistemographic pattern of communicating hydrocephalus tended to show more severe degrees of lateral ventricular dilatation, with involvement of the third and fourth ventricles and relative sparing of the cerebral sulci. Patients with a cistemographic pattern of cerebral atrophy showed lesser degrees of lateral ventricular dilatation and more severe degrees of dilatation of the cerebral sulci. The statistical significance of the individual CTT findings in these patients is presented, and a scheme for interpretation is proposed. The study shows that CTT can replace pneumoencephalography in evaluating patients with dementia, while cisternography contributes complementary information.

Computed tomography was performed on 5 children with posterior fossa cystic abnormalities. On an axial tomogram, an enlarged cisterna magna could not be distinguished from a Dandy-Walker variant, nor could an encysted fourth ventricle be distinguished from a subarachnoid cyst. Supplementary air encephalography or sagittal reconstruction of tomograms is necessary to define posterior fossa cysts accurately.

Evaluation of computed tomography of the normal larynx has been performed utilizing corresponding tomographic and anatomic planes. The transaxial, coronal, and sagittal planes have been evaluated. While all three planes have distinct potential diagnostic value, the transaxial plane offers a unique view of laryngeal structures not afforded by any other technique. It is hoped that diagnostic criteria developed in this study will prove applicable to the evaluation of clinical laryngeal disease.

In this retrospective study, the accuracy of preoperative staging by high‐resolution CT and clinical evaluation (indirect‐direct laryngoscopy) is compared to the postsurgical pathologic staging of laryngeal cancer. Forty‐two patients who were admitted to St. Louis University Hospital between the years of 1978 to 1985 with diagnoses of laryngeal cancer were included. All patients received high‐resolution CT scan of the larynx preoperatively and subsequently underwent total or partial laryngectomy. None of these patients received preoperative radiotherapy. The accuracy of the clinical vs. CT staging—as well as the accuracy of the staging by combination of the two modalities—was determined by comparison with the postsurgical pathologic staging. The accuracy was assessed separately for glottic, supraglottic, and transglottic carcinoma. The accuracy of CT staging for glottic carcinoma was 75%. However, clinical evaluation in this group of lesions was very reliable, offering 92.9% accuracy. The accuracy of CT staging increased in the supraglottic and transglottic lesions, to become superior to the clinical staging. With combined information gained by both examinations, the preoperative staging accuracy was 91.4% for supraglottic carcinoma and 87.5% for transglottic carcinoma. It is, therefore, recommended that high‐resolution CT should be included in the preoperative staging of laryngeal cancer.

Abstract Twenty‐seven cancerous larynges were examined preoperatively by computed tomography and postoperatively by transaxial anatomic sections. Data from this correlative study provides a new radiographic classification based upon the relationship of the plane of maximal tumor size to the apex, body, or vocal process of the arytenoid. Unlike those tumors whose maximal size lies at or above the apex of the arytenoid, those below have a very high association with cartilage invasion (8% in former group, 86% in latter group). This is explained by our observation of sites of predilection of tumor invasion of the thyroid, cricoid, and arytenoid cartilages. At these sites collagen fibers have been observed to pass through the perichondrium and attach directly to cartilage. These same fibers may serve as a pathway to direct growth of tumor cells. There was no correlation between six histologic parameters and the presence of cartilage invasion.

✓ A 48-year-old laborer presented with a 1-year history of low-back pain radiating into the posterior aspects of both thighs. Two weeks before admission, acute exacerbation resulted in signs and symptoms of compressive radiculopathy at L-5. Myelography revealed concentric constriction of the lower thecal sac due to abundant fat, as shown by computerized tomography. Laminectomy produced immediate relief of pain. The significance of these findings and a review of the literature are presented.

Three children presented at birth with axial hypotonia and symmetrical flaccid paresis limited to the upper extremities, and involving proximal and distal muscle groups. At birth, palmar flexion creases were poorly developed, and the hand muscles were atrophic. These clinical features, the muscle biopsy findings, and the nonprogressive course, suggest a vascular insult to the cervical spinal cord during gestation. The term, congenital cervical spinal atrophy seems most descriptive of these features.

Six cases of laryngeal cancer have been examined by computed tomography. The findings were correlated with those obtained by laryngos-copty and in five cases by pathological examination of the surgical specimens. Computed tomography accurately delineated the extent of tumor involvement of the laryngeal and paralyryngeal soft tissues. The diagnosis of involvement of the laryngeal cartilages presents some problems, which are discussed.

A full-term infant who demonstrated a prolonged period of obtundation following asphyxia at birth was found on cranial computed tomography (CT) to have hemorrhage limited exclusively to symmetric bithalamic and striatal areas. This pattern of discrete, symmetric nuclear hemorrhage has not so far been reported as a complication of birth asphyxia. It differs from the germinal matrix hemorrhage on one hand in having a later time of onset (between the 4th and 10th day of life). It is also distinct from the more common supratentorial parenchymal hemorrhages in full-term infants owing to its topography, consequent interruption of the thalamocortical arousal mechanisms, and prolonged period of obtundation.

Abstract The results of a correlative study between computed tomography (CT) and transaxial histopathologic sections from cancerous larynges are presented. CT has proved highly reliable in accurately delineating the extent of tumor, but there remain problems of which the interpreter must be aware. This paper is designed to illustrate application of CT examination to the problem of cancer of the larynx.

The most commonly accepted classification of laryngeal cancer is based on the definition of regions formulated by the American Joint Committee on Laryngeal Cancer. The limitations of this classification are discussed. A new radiologic classification based on computed tomography (CT) is presented, its application illustrated, and its accuracy documented. This classification has the advantage that it provides information preoperatively which closely agrees with the pathologic facts seen postoperatively. It also helps to separate those tumors that tend to invade cartilage from those that do not. Cancer 53:44-57, 1984.

An 11-year-old boy with Kearns-Sayre syndrome developed hypersomnia associated with bithalamic lesions and had complete absence of sleep spindles on a nocturnal polysomnogram.

Angiographic features in three cases of hemangioblastoma arising from the posterior aspect of the medulla oblongata are compared with those found in a case of hemangioblastoma of the cerebellar tonsil. All cases displayed a dense stain of the nodular portion of the lesion, a mass effect of the cystic portion, and early filling of draining veins. Medullary lesions produced separation of the posterior medullary segments and the choroidal loops of the posterior inferior cerebellar arteries (PICA). The tonsillar lesion stretched the supratonsillar segments and displaced the ipsilateral PICA branches to the opposite side across the midline.

Epidermoid and dermoid tumors are uncommon lesions and within the spinal cord are rare. Magnetic resonance imaging has proved sensitive to their detection in the intracranial cavity but the pattern of signal intensities on T1 and T2 weighted images has not been uniform. Utilizing a 0.6 T superconductive magnet an intrarnedullary cervical dermoid tumor was examined. The correlation between CT demonstrated regions of fat density and the MRI appearance of comparable regions of high intensity signal on T1 weighted images has only rarely been demonstrated in such tumors that have no histologic evidence of adipose tissue. MRI provided all of the information needed pre-operatively.

The internal structures of specimens of the knee can be visualized by computed tomography, although visualization is directly dependent on a thin (3 mm) scan in the coronal or sagittal plane with air used as a contrast agent.

A 33-month-old boy with recurrent stroke-like episodes had angiographic features characteristic of moyamoya syndrome. Mitochondrial encephalomyopathy was suspected because of lactic acidosis and ptosis. Studies of oxidative metabolism on isolated skeletal muscle mitochondria revealed impairment of NADH-coenzyme Q reductase activity. Mitochondrial metabolic disorders may cause moyamoya syndrome when other known associated factors are absent.

Summary To date, only anectodal clinical data exist pertaining to the histological changes of hydroxyapatite within an enucleated socket. This study was conducted to determine the histological and radiological changes in a coralline hydroxyapatite sphere placed into the central socket, in a controlled fashion. Rabbits underwent simple enucleation with implantation of an autologous sclera-wrapped hydroxyapatite spheres with extraocular muscle reattachment. Preoperatively, the mineral density of each sphere was determined using quantitative computed tomography (CT) that was repeated 2− and 6 weeks postoperatively. The implants were harvested at 2− and 6 weeks and submitted for light and electron microscopic analysis. The results demonstrated a uniform influx of fibrovascular tissue that did not reach the center of the implant, even at 6 weeks. A marked mixed-cell inflammatory response was noted at the interface between the fibrovascular tissue and the hydroxyapatite. Giant cells were noted only at the scierai windows. This study demonstrated that the early response to hydroxyapatite implants was fibrovascular ingrowth with mixed-cell inflammation. These histological observations correlated with findings observed with quantitative CT. Quantitative CT appears to be an ideal modality for observing the early temporal tissue density changes in hydroxyapatite implants.

A computed tomographic analysis of normal laryngeal anatomy was undertaken using cadaver larynxes. This was part of a larger project in which patients with laryngeal carcinoma were routinely evaluated in the computed tomographic (CT) body scanner. The appearance of normal laryngeal anatomy had to be delineated before disease processes of the larynx were evaluated, and this was accomplished using a computed tomographic technique with 5-mm slice thicknesses and a 3-mm overlap. The scan slices were then compared with anatomic sections taken at the same levels. The comparisons demonstrate an ideal level of accuracy that can be approached in the in-vivo larynx only with use of the latest-generation scanners. However, CT scanning is of immediate usefulness in the diagnosis of laryngeal pathology.

The computed tomography (CT) scans and laryngograms of 25 patients with laryngeal cancer were compared and evaluated in an assessment of the diagnostic accuracy of each modality in the supraglottic, glottic, and subglottic regions. Fourth generation scanners were used in these patients, all of whom subsequently underwent laryngectomy or partial laryngectomy. The clinical superiority of CT scanning was evident in several areas--confirming clinical impressions that laryngography is not as accurate as CT, is frequently misleading, and offers no significant advantages over CT. In this regard, we now believe that computed tomography is the most important radiologic adjunct in the diagnosis of laryngeal cancer, and we no longer order the laryngogram on a routine basis.

Eight cases with fractures of the sphenoid bone are discussed. In four the sella turcica was involved. One showed bilateral fractures of the medial pterygoid plates resulting in an open-bite deformity. Another patient exhibited bilateral carotid-cavernous fistulae. This brings the total of documented, angiographically demonstrated, post-traumatic, bilateral, carotid-cavernous fistulae to seven. Fractures of the planum sphenoidale, the floor of the sphenoid sinus, and bilateral fractures of the lesser wings are also shown. The anatomy of the sphenoid bone and clinical sequelae are briefly discussed.

Neither laryngoscopy nor laryngography can match the accuracy with which computed tomography (CT) can display the full tumor extent or the presence of cartilage invasion. Data obtained from a CT-histologic correlative study have suggested a new definition of regions of the larynx for use with the TNM staging of laryngeal cancer. The arytenoid cartilage, readily identifiable by CT, is used for reference. The regions are as follows: (a) supra-arytenoid, (b) midarytenoid, (c) vocal process, and (d) infra-arytenoid. Tumors with a strong propensity for cartilage invasion can be distinguished from those without this tendency. In addition, tumors with different pathways of lymphatic drainage can be identified.

The clinical and radiological findings of thirteen patients with Arnold-Chiari malformation presenting in adult life are described. Only one-half of these patients had abnormalities on plain cervical radiographs. The diagnostic radiographic abnormalities are discussed but without a high index of suspicion this condition may be confused with multiple sclerosis or syringomyelia. A review of the pathological findings accounting for the symptoms and a review of the literature are included.

A 64-year-old woman with a long-stand ing deformity of the neck presented with a rapidly enlarging neck mass following sud den turning of the head. Cervical radio graphs demonstrated a large erosion of the posterior elements of the cervical vertebra at the site of the deformity, and angiography revealed an aneurysmal sac of the left verte bral artery. The differential diagnoses of en larging neck masses associated with these ra diographic findings are discussed.

A 4-year-old Caucasian male presented with marked proptosis of the right eye of 3 months“ duration. A large soft tissue mass occupied fully the right ethmoid sinus; radiologic evidence of extensive bone destruction suggested a malignant tumor. Unexpectedly, a biopsy of the ethmoid tumor was interpreted as benign. Over the next 2 months, this lesion progressed rapidly, with further bone destruction and extension into the anterior cranial fossa. The histopathologic features of a resection specimen were so variable that a wide range of diagnoses was offered by several consultants who examined the material. This lack of agreement among experts in the field of bone diseases considerably influenced the treatment program selected for this patient.

The purpose of our study was to determine serial mineral density changes in coralline hydroxyapatite orbital implants after implantation into the human socket. Prospective analysis by quantitative computed tomography determined the mineral density of hydroxyapatite orbital implants in five patients before and at two time intervals after implantation. Mineral density of the spheres increased an average of 135% after implantation (3-8 months) from preoperative measurements. The density continued to rise an average of 5% (range, -9%-16%) at the second postoperative period (22-39 months). Average follow-up was 30 months. The increased density in the nonevisceration patients was noted in the regions of the scleral windows and the exposed posterior implant where the cornea had been removed from the scleral wrap. The mineral density of hydroxyapatite spheres markedly increases after implantation. Approximately 2 to 3 years later, the densities continue to increase slightly in enucleation and secondary implant cases. An evisceration implant was the only implant to lose density. This study shows no decrease in the mineral density of orbital coralline hydroxyapatite enucleation implants, suggesting a lack of implant mineral resorption.

The surgery of hyperparathyroidism can be technically very difficult, even for an experienced surgeon. Until the present decade, preoperative localization procedures were of little help because of poor resolution of imaging modalities, significant morbidity, and the cost of invasive procedures. The efficacy of preoperative high-resolution CT scanning was evaluated in ten patients with primary hyperparathyroidism who had not previously been operated on. Contrast and noncontrast scans were performed on each patient, under the supervision of an experienced radiologist. Surgical findings were the standard against which all CT scans were judged. Each patient was diagnosed as having a single adenoma. Preoperative scans localized eight of ten adenomas for an overall sensitivity of 80 percent. In one patient, the adenoma was incorrectly localized for a specificity of 89 percent. The smallest adenoma correctly localized measured 4 x 4 mm in its axial dimensions. In addition to shortening operative time, accurate preoperative localization permitted use of unilateral dissection technique. Recent literature has repeatedly proved unilateral dissection superior to bilateral dissection by production of identical cure rates and a 2- to 12-fold decrease in postoperative hypocalcemia. We suggest that CT scanning be considered in the routine preoperative workup of patients who have primary hyperparathyroid disease.

The clinical and radiographic features of cerebral deep venous thrombosis in a 21-year-old white woman are presented. This nulliparous patient presented with relatively mild clinical symptoms and progressing mental status changes. The only known risk factor was "low-dose" oral contraceptive pills. The magnetic resonance image (MRI) showed increased signal intensity from the internal cerebral veins, vein of Galen, and straight sinus. The diagnosis was confirmed by arterial angiography.

Contrary to what is frequently stated in the literature, preoperative localization of parathyroid adenomas is important. Surgery limited to removal of the adenoma is associated with significantly less morbidity than when bilateral exploration is undertaken. In fact, a 2 to 12 fold decrease in post-operative hypocalcemia has been reported when the surgical exploration is unilateral. Pre-operative CT scans localized 10 of 13 surgically proven adenomas for an overall detection rate of 77%. Only one adenoma in our series had an average axial diameter of greater than 1 cm, the smallest measuring 5 mm × 3 mm. This paper outlines our CT technique and results and summarizes the pertinent recent surgical literature in reference to the importance of preoperative localization.

Quantitative computed tomography (qCT) can be employed to determine the mineral density (MD) of bone or similar mineralized alloplastic materials with high precision. Porous spheres made from coralline hydroxy-apatite are currently used for reconstruction after enucleation procedures. The long-term fate of these implants is unknown. Using qCT, MD was determined in hydroxyapatite spheres prior to implantation. Intersphere MD varied up to 200% with a near Gaussian distribution. Intrasphere MD did not vary significantly when comparing central to peripheral sites. The density of coralline hydroxyapatite spheres was ~400% greater than the density of newly formed endochondral bone. This study demonstrates that qCT data were an invaluable tool for MD determination, detecting a marked variability in hydroxyapatite MDs. Because the long-term fate of these implants is unknown and fibro-vascular ingrowth is an important event in the integration of these implants, monitoring of MDs of coralline hydroxyapatite implants is of interest.

Gross anatomic sections of isolated temporal bones (TB) were compared with high resolution computed tomography (CT) scans obtained utilizing contiguous 1.5-mm thick slices in the transaxial, coronal, and sagittal planes. Each TB was then sectioned at 2.0-mm intervals in planes paralled to those of the CT scans. Both the cochlear and vestibular aqueducts were best visualized in the coronal plane; the transaxial plane proved less reliable and the sagittal plane was not useful at all. The cochlear aqueduct in the coronal plane appears as a funnel-shaped configuration with its widest portion opening into the subarachnoid space. The vestibular aqueduct at its opening-into the epidural space is well visualized in the coronal plane, and as it traverses the bone toward the vestibule it appears as an oval to spherical lucency, whereas in transaxial sections it is seen as a small longitudinal lucency.

This chapter will attempt to shed light on the relevant explanations for designating or creating urban agglomeration for the purpose of administration and governance in the case of largest urban space in Jamaica. The main objective of this chapter is to provide an in-depth look at the case of Portmore with specific emphasis on the socio-economic, political, legislative, and relevant policy arrangements that influence the change in sub-national geo-political status from municipality to parish. The researchers explore the literature on local government reform, public financing, urban economics, and urban planning which provided a basis for objectively interrogating the proposed change. From the analysis of existing legislations, policies, and international conventions such as the New Urban Agenda, the proposal to change the geo-political designation of the Municipality of Portmore raises several questions about the economic profile of the area and the capacity to enjoy the benefits of urban agglomeration given its location attributes. Understanding the evolution of the theoretical discourse in urban planning can provide clarity on the relevance of this geo-political designation, the intergovernmental relationship associated with the geo-political designation, particularly as it relates to autonomy, and the allocation of resources for the provision of local government services. This understanding will help to direct the decision makers as to the best designation for Portmore given its current realities and importance of implementing measures to support decentralization and autonomy at the local level for major urban areas. The researchers found that the economic viability of the proposition is at best questionable as the economic base of the municipality is limited and its capacity to generate linkages demand serious considerations. Attention should be given to local government reform in the face of emerging trends and current realities rather than changing status of an urban areas which is the direct result of the principles of urban agglomeration.

Linear areas of periventricular calcification may evolve during the initial weeks following onset of severe neonatal bacterial meningitis complicated by ventriculitis. Two infants with this hitherto undescribed finding, studied with serial computed tomography, are reported.

The purpose of this article has been to provide the results of a survey of the more common conditions, and their CT findings, causing chronic low back pain. There is an extensive literature on this subject, providing much more detail and discussing less common entities, of which the reader may avail himself.

III. Preliminary results of radiotherapy and a

A study of the findings on cisternograms and computerized transaxial tomography (CTT) of 44 patients showed good correlation between the two tests. Patients with a cisternographic pattern of communicating hydrocephalus tended to show more severe degrees of lateral ventricular dilatation, with involvement of the third and fourth ventricles and relative sparing of the cerebral sulci. Patients with a cisternographic pattern of cerebral atrophy showed lesser degrees of lateral ventricular dilatation and more severe degrees of dilatation of the cerebral sulci. The statistical significance of the individual CTT findings in these patients is presented, and a scheme for interpretation is proposed. The study shows that CTT can replace pneumoencephalography in evaluating patients with dementia, while cisternography contributes complementary information.

The normal anatomy of the larynx as displayed on computed tomography is illustrated. Pathologic alterations in patients with carcinoma of the larynx are depicted and discussed.Computed tomography is recommended as the initial radiologic procedure when additional diagnostic information is required to supplement the findings of laryngoscopy; it will help to determine whether conservative surgery as opposed to total laryngectomy is possible.

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