Xin Lou

Theranostic nanoagents are promising for precision medicine. However, biodegradable nanoagents with the ability for photoacoustic (PA) imaging guided photothermal therapy (PTT) are rare. We herein report the development of biodegradable semiconducting polymer nanoparticles (SPNs) with enhanced PA and PTT efficacy for cancer therapy. The design capitalizes on the enzymatically oxidizable nature of vinylene bonds in conjunction with polymer chemistry to synthesize a biodegradable semiconducting polymer (DPPV) and transform it into water-soluble nanoparticles (SPNV). As compared with its counterpart SPN (SPNT), the presence of vinylene bonds within the polymer backbone also endows SPNV with a significantly enhanced mass absorption coefficient (1.3-fold) and photothermal conversion efficacy (2.4-fold). As such, SPNV provides the PA signals and the photothermal maximum temperature higher than SPNT, allowing detection and photothermal ablation of tumors in living mice in a more sensitive and effective way. Our study thus reveals a general molecular design to enhance the biodegradability of optically active polymer nanoparticles while dramatically elevating their imaging and therapeutic capabilities.

Excess iron deposition in the brain often causes oxidative stress-related damage and necrosis of dopaminergic neurons in the substantia nigra and has been reported to be one of the major vulnerability factors in Parkinson's disease (PD). Iron chelation therapy using deferoxamine (DFO) may inhibit this nigrostriatal degeneration and prevent the progress of PD. However, DFO shows very short half-life in vivo and hardly penetrates the blood brain barrier (BBB). Hence, it is of great interest to develop DFO formulations for safe and efficient intracerebral drug delivery. Herein, we report a polymeric nanoparticle system modified with brain-targeting peptide rabies virus glycoprotein (RVG) 29 that can intracerebrally deliver DFO. The nanoparticle system penetrates the BBB possibly through specific receptor-mediated endocytosis triggered by the RVG29 peptide. Administration of these nanoparticles significantly decreased iron content and oxidative stress levels in the substantia nigra and striatum of PD mice and effectively reduced their dopaminergic neuron damage and as reversed their neurobehavioral deficits, without causing any overt adverse effects in the brain or other organs. This DFO-based nanoformulation holds great promise for delivery of DFO into the brain and for realizing iron chelation therapy in PD treatment.

The recovery process of COVID-19 patients is unclear. Some recovered patients complain of continued shortness of breath. Vasculopathy has been reported in COVID-19, stressing the importance of probing pulmonary microstructure and function at the alveolar-capillary interface. While computed tomography (CT) detects structural abnormalities, little is known about the impact of disease on lung function. 129Xe magnetic resonance imaging (MRI) is a technique uniquely capable of assessing ventilation, microstructure, and gas exchange. Using 129Xe MRI, we found that COVID-19 patients show a higher rate of ventilation defects (5.9% versus 3.7%), unchanged microstructure, and longer gas-blood exchange time (43.5 ms versus 32.5 ms) compared with healthy individuals. These findings suggest that regional ventilation and alveolar airspace dimensions are relatively normal around the time of discharge, while gas-blood exchange function is diminished. This study establishes the feasibility of localized lung function measurements in COVID-19 patients and their potential usefulness as a supplement to structural imaging.

This article focuses on clinical applications of arterial spin labeling (ASL) and is part of a wider effort from the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group to update and expand on the recommendations provided in the 2015 ASL consensus paper. Although the 2015 consensus paper provided general guidelines for clinical applications of ASL MRI, there was a lack of guidance on disease‐specific parameters. Since that time, the clinical availability and clinical demand for ASL MRI has increased. This position paper provides guidance on using ASL in specific clinical scenarios, including acute ischemic stroke and steno‐occlusive disease, arteriovenous malformations and fistulas, brain tumors, neurodegenerative disease, seizures/epilepsy, and pediatric neuroradiology applications, focusing on disease‐specific considerations for sequence optimization and interpretation. We present several neuroradiological applications in which ASL provides unique information essential for making the diagnosis. This guidance is intended for anyone interested in using ASL in a routine clinical setting (i.e., on a single‐subject basis rather than in cohort studies) building on the previous ASL consensus review.

<h3>Background</h3> Auditory neuropathy spectrum disorder (ANSD) is a form of hearing loss in which auditory signal transmission from the inner ear to the auditory nerve and brain stem is distorted, giving rise to speech perception difficulties beyond that expected for the observed degree of hearing loss. For many cases of ANSD, the underlying molecular pathology and the site of lesion remain unclear. The X-linked form of the condition, AUNX1, has been mapped to Xq23-q27.3, although the causative gene has yet to be identified. <h3>Methods</h3> We performed whole-exome sequencing on DNA samples from the AUNX1 family and another small phenotypically similar but unrelated ANSD family. <h3>Results</h3> We identified two missense mutations in <i>AIFM1</i> in these families: c.1352G&gt;A (p.R451Q) in the AUNX1 family and c.1030C&gt;T (p.L344F) in the second ANSD family. Mutation screening in a large cohort of 3 additional unrelated families and 93 sporadic cases with ANSD identified 9 more missense mutations in <i>AIFM1</i>. Bioinformatics analysis and expression studies support this gene as being causative of ANSD. <h3>Conclusions</h3> Variants in <i>AIFM1</i> gene are a common cause of familial and sporadic ANSD and provide insight into the expanded spectrum of <i>AIFM1</i>-associated diseases. The finding of cochlear nerve hypoplasia in some patients was <i>AIFM1</i>-related ANSD implies that MRI may be of value in localising the site of lesion and suggests that cochlea implantation in these patients may have limited success.

Multiple b-value gas diffusion-weighted MRI (DW-MRI) enables non-invasive and quantitative assessment of lung morphometry, but its long acquisition time is not well-tolerated by patients. We aimed to accelerate multiple b-value gas DW-MRI for lung morphometry using deep learning.A deep cascade of residual dense network (DC-RDN) was developed to reconstruct high-quality DW images from highly undersampled k-space data. Hyperpolarized 129Xe lung ventilation images were acquired from 101 participants and were retrospectively collected to generate synthetic DW-MRI data to train the DC-RDN. Afterwards, the performance of the DC-RDN was evaluated on retrospectively and prospectively undersampled multiple b-value 129Xe MRI datasets.Each slice with size of 64 × 64 × 5 could be reconstructed within 7.2 ms. For the retrospective test data, the DC-RDN showed significant improvement on all quantitative metrics compared with the conventional reconstruction methods (p < 0.05). The apparent diffusion coefficient (ADC) and morphometry parameters were not significantly different between the fully sampled and DC-RDN reconstructed images (p > 0.05). For the prospectively accelerated acquisition, the required breath-holding time was reduced from 17.8 to 4.7 s with an acceleration factor of 4. Meanwhile, the prospectively reconstructed results showed good agreement with the fully sampled images, with a mean difference of -0.72% and -0.74% regarding global mean ADC and mean linear intercept (Lm) values.DC-RDN is effective in accelerating multiple b-value gas DW-MRI while maintaining accurate estimation of lung microstructural morphometry, facilitating the clinical potential of studying lung diseases with hyperpolarized DW-MRI.• The deep cascade of residual dense network allowed fast and high-quality reconstruction of multiple b-value gas diffusion-weighted MRI at an acceleration factor of 4. • The apparent diffusion coefficient and morphometry parameters were not significantly different between the fully sampled images and the reconstructed results (p > 0.05). • The required breath-holding time was reduced from 17.8 to 4.7 s and each slice with size of 64 × 64 × 5 could be reconstructed within 7.2 ms.

To assess the reliability and reproducibility of pseudo-continuous arterial spin labeling (pCASL). Intra- and interscanner reliability and reproducibility are essential before pooling perfusion imaging data.Eight volunteers were scanned three times on two 3.0T magnetic resonance imaging (MRI) scanners using the pCASL technique. The first and third tests were conducted on scanner one, while the second test was on scanner two. The pCASL was acquired with postlabeling delay time (PLD) of 1.5 and 2.5 seconds. The cerebral blood flow (CBF) of gray matter, white matter, frontal lobe, parietal lobe, occipital lobe, temporal lobe, putamen, posterior cingulate, and thalamus were extracted for comparison. Reliability and reproducibility were measured using the intraclass correlation coefficient (ICC) and within-subject coefficients of variation (wsCV), respectively.The pCASL consistently had high intra- and interscanner measurement reliability and reproducibility. Reproducibility of the CBF values was higher, with PLD 2.5 seconds than with PLD 1.5 seconds. Different PLDs had considerable influence on the reproducibility of the different regions of the brain.Although excellent intra- and interscanner reliability and reproducibility could support the feasibility of cross-site pooling of ASL data, pCASL with multiple PLDs may better assess the CBF of the human brain.

MRI-guided focused ultrasound (MRgFUS) thalamotomy is a novel and minimally invasive alternative for medication-refractory tremor in Parkinson's disease (PD). However, the impact of MRgFUS thalamotomy on spontaneous neuronal activity in PD remains unclear. The purpose of the current study was to evaluate the effects of MRgFUS thalamotomy on local fluctuations in neuronal activity as measured by the fractional amplitude of low-frequency fluctuations (fALFF) in patients with PD.Participants with PD undergoing MRgFUS thalamotomy were recruited. Tremor scores were assessed before and 3 and 12 months after treatment using the Clinical Rating Scale for Tremor. MRI data were collected before and 1 day, 1 week, 1 month, 3 months, and 12 months after thalamotomy. The fALFF was calculated. A whole-brain voxel-wise paired t-test was used to identify significant changes in fALFF at 12 months after treatment compared to baseline. Then fALFF in the regions with significant differences were extracted from fALFF maps of patients for further one-way repeated-measures ANOVA to investigate its dynamic alterations. The association between fALFF changes induced by thalamotomy and tremor improvement were evaluated using the nonparametric Spearman rank test.Nine participants with PD (mean age ± SD 64.7 ± 6.1 years, 8 males) were evaluated. Voxel-based analysis showed that fALFF in the left occipital cortex (Brodmann area 17 [BA17]) significantly decreased at 12 months after thalamotomy compared to baseline (voxel p < 0.001, cluster p < 0.05 family-wise error [FWE] corrected). At baseline, fALFF in the left occipital BA17 in patients was elevated compared with that in 9 age- and gender-matched healthy subjects (p < 0.05). Longitudinal analysis displayed the dynamic changes of fALFF in this region (F (5,40) = 3.61, p = 0.009). There was a significant positive correlation between the falling trend in fALFF in the left occipital BA17 and hand tremor improvement after treatment over 3 time points (Spearman's rho = 0.44, p = 0.02).The present study investigated the impact of MRgFUS ventral intermediate nucleus thalamotomy on spontaneous neural activity in medication-refractory tremor-dominant PD. The visual area is, for the first time, reported as relevant to tremor improvement in PD after MRgFUS thalamotomy, suggesting a distant effect of MRgFUS thalamotomy and the involvement of specific visuomotor networks in tremor control in PD.

We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values.Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed.The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 × 10(-3) mm(2)/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively.pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors.• pCASL shows positive correlation with DSC-PWI in astrocytic tumour grading. • ADC values based on ADC histograms can be an objective method. • Combination of DWI and pCASL or DSC-PWI can improve grading accuracy.

Three-dimensional pseudocontinuous arterial spin labeling with multiple postlabeling delays has been used to assess cerebral blood flow (CBF). We used this modality to estimate antegrade and collateral flow in patients with unilateral middle cerebral artery stenosis.Consecutive patients with unilateral middle cerebral artery 50% to 99% stenosis at 2 centers underwent pseudocontinuous arterial spin labeling with a postlabeling delays of 1.5 and 2.5 s. Mean CBF of bilateral middle cerebral artery territory at the postlabeling delays 1.5 and 2.5 s was measured. Early-arriving flow proportion was defined as (CBF 1.5 s at lesion side/CBF 2.5 s at normal side)×100%. Late-arriving retrograde flow proportion was defined as ([CBF 2.5 s-CBF 1.5 s] at lesion side-[CBF 2.5 s-CBF 1.5 s] at normal side)/CBF 2.5 s at normal side×100%. Antegrade and collateral scales were evaluated in patients with conventional angiography. Spearman correlation coefficients were calculated between early-arriving flow and late-arriving retrograde flow proportions on arterial spin labeling and antegrade and collateral scales on conventional angiography, respectively.Forty-one patients (46.0±12.0 years) were enrolled. The mean early-arriving flow proportion was 78.3±14.9%. The mean late-arriving retrograde flow proportion was 16.1±10.2%. In 21 patients with conventional angiography, Spearman correlation coefficient was 0.53 (95% confidence interval, 0.11-0.79) between antegrade grade and early-arriving flow proportion (P=0.01) and 0.81 (95% confidence interval, 0.56-0.92) between collateral grade and late-arriving retrograde flow proportion (P<0.0001).Three-dimensional pseudocontinuous arterial spin labeling with 2 postlabeling delays may provide an empirical approach for estimating antegrade and collateral flow in patients with unilateral middle cerebral artery stenosis.URL: http://www.clinicaltrials.gov. Unique identifier: NCT02479243.

Multi-delay arterial spin-labeling (ASL) perfusion imaging has been used as a promising modality to evaluate cerebral perfusion. Our aim was to assess the association of leptomeningeal collateral perfusion scores based on ASL parameters with outcome of endovascular treatment in patients with acute ischemic stroke (AIS) in the middle cerebral artery (MCA) territory.ASL data at 4 post-labeling delay (PLD) times (PLD = 1.5, 2, 2.5, 3 s) were acquired during routine clinical magnetic resonance examination on AIS patients prior to endovascular treatment. A 3-point scale of leptomeningeal collateral perfusion grade on 10 anatomic regions was determined based on arterial transit times (ATT), cerebral blood flow (CBF), and arterial cerebral blood volume (CBV), estimated by the multi-delay ASL protocol. Based on a 90-day modified Rankin Scale (mRS), the patients were dichotomized to moderate/good (mRS 0-3) and poor outcome (mRS 4-6) and the regional collateral flow scores were compared.Fifty-five AIS patients with unilateral MCA stroke (mean 73.95±14.82 years) including 23 males were enrolled. Compared with poor outcome patients, patients with moderate to good outcomes had a significantly higher leptomeningeal collateral perfusion scores on CBV (3.01±2.11 vs. 1.82±1.51, p=0.024) but no differences on scores on CBF (2.31±1.61 vs. 1.66±1.32, p=0.231) and ATT (2.67±2.33 vs. 3.42±3.37, p=0.593).Higher leptomeningeal collateral perfusion scores on CBV images by ASL may be a specific marker of clinical outcome after endovascular treatment in patients with acute MCA ischemic stroke. Further study with larger sample size is warranted.

Our purpose is to assess the role of cerebral small vessel disease (SVD) in prediction models in patients with different subtypes of acute ischemic stroke (AIS).We enrolled 398 small-vessel occlusion (SVO) and 175 large artery atherosclerosis (LAA) AIS patients. Functional outcomes were assessed using the modified Rankin Scale (mRS) at 90 days. MRI was performed to assess white matter hyperintensity (WMH), perivascular space (PVS), lacune, and cerebral microbleed (CMB). Logistic regression (LR) and machine learning (ML) were used to develop predictive models to assess the influences of SVD on the prognosis.In the feature evaluation of SVO-AIS for different outcomes, the modified total SVD score (Gain: 0.38, 0.28) has the maximum weight, and periventricular WMH (Gain: 0.07, 0.09) was more important than deep WMH (Gain: 0.01, 0.01) in prognosis. In SVO-AIS, SVD performed better than regular clinical data, which is the opposite of LAA-AIS. Among all models, eXtreme gradient boosting (XGBoost) method with optimal index (OI) has the best performance to predict excellent outcome in SVO-AIS. [0.91 (0.84-0.97)].Our results revealed that different SVD markers had distinct prognostic weights in AIS patients, and SVD burden alone may accurately predict the SVO-AIS patients' prognosis.

Glioma genotypes are of importance for clinical decision-making. This data can only be acquired through histopathological analysis based on resection or biopsy. Consequently, there is a need for alternative biomarkers that noninvasively provide reliable information for preoperatively identifying molecular characteristics.To investigate apparent diffusion coefficient (ADC) as imaging biomarker for preoperatively identifying glioma genotypes based on the 2021 World Health Organization (WHO) classification of central nervous system (CNS) tumors.Retrospective.One hundred and fifty-nine patients (47.6 ± 14.4 years) diagnosed with WHO grade 2-4 glioma including 93 males and 66 females.A 3 T/spin echo echo planner imaging.The ADC measurements were assessed by two neuroradiologists (both with 6 years of experience). Three different lowest portions inside the tumors without overlap were manually drawn on the ADC maps as regions of interest (ROIs). The mean ADC value of the three ROIs was defined as the minimum ADC value (ADCmin ). An ROI was placed in the contralateral normal appearing white matter (NAWM) to obtain the ADC value (ADCNAWM ). The ADCmin to ADCNAWM ratio (ADCratio ) was calculated. Genetics results were retrospectively recorded from pathologic and genetic test reports.Two-sample independent t-tests, receiver operating characteristic curve analysis, and intraclass correlation coefficient analysis were used. Statistical significance was set at P < 0.05.Isocitrate dehydrogenase (IDH)-mutated glioma showed higher ADCmin and ADCratio than IDH wild-type glioma. Among IDH-mutated glioma, higher ADCmin and ADCratio were found in 1p19q intact glioma than in 1p19q codeletion glioma. ADC parameters enabled differentiation of IDH mutation status with area under the curve (AUC) of 0.84 and 0.86.ADC has potential discriminative value for IDH mutation and 1p19q codeletion status.3.Stage 2.

Meningeal melanocytoma is an uncommon pigmented neoplasm that affects the CNS and develops in the cranial and spinal leptomeninges. Here we report on a case of malignant transformation of intracranial supratentorial meningeal melanocytoma which recurred after 3 years as malignant melanoma. This case demonstrates that the biological behavior of melanocytoma is uncertain and that these lesions may recur as malignant melanoma.

Purpose To investigate the topologic architecture of white matter connectivity networks in preschool-aged children with a diagnosis of autism spectrum disorder (ASD) versus typical development (TD). Materials and Methods Forty-two participants were enrolled, including 21 preschool children with ASD (14 male children and seven female children; mean age, 4.56 years ± 0.97 [standard deviation]) and 21 children with TD (11 males and 10 females; mean age, 5.13 years ± 0.82). The diagnosis of ASD was determined according to the Diagnostic and Statistical Manual of Mental Disorders Global Assessment of Functioning scores (mean score, 8.00 ± 0.50). All participants underwent diffusion-tensor imaging (DTI) and T2-weighted imaging on a 3-T magnetic resonance system. A graph theoretical analysis was applied to investigate the topologic organization of the brain network including global and local topologic parameters. Statistical analysis was then performed for the comparison between the groups. Results Compared with the TD group, children with ASD demonstrated shortened characteristic path length (t1 = 0.536, t2 = 0.534, t3 = 0.523, t4 = 0.510, and t5 = 0.501; P < .05) and increased global efficiency (t1 = 0.499, t2 = 0.497, t3 = 0.486, t4 = 0.473, and t5 = 0.465; P < .05) and clustering coefficient (t1 = 0.673, t2 = 0.750, t3 = 0.757, t4 = 0.738, and t5 = 0.741; P < .05). Significant increases in nodal efficiency were mainly found in left pallidum (0.037 vs 0.032, respectively; P < .01) and right caudate nucleus (0.037 vs 0.032, respectively; P < .01) of the basal ganglia network. Conclusion Significantly altered patterns of global and local brain network topography may underlie the abnormal brain development in preschool children with ASD compared with those who have TD. The identification of altered structural connectivity in basal ganglia and paralimbic-limbic networks may point toward potential imaging biomarkers for preschool-age patients with ASD. © RSNA, 2018.

The purpose was to assess the difference of collaterals in symptomatic versus asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis by comparing cerebral blood flow (CBF) at two post labeling delays (PLD) using three-dimensional pseudo-continuous arterial spin labeling (3D pCASL). Eighty-one patients (49 symptomatic and 32 asymptomatic) with unilateral MCA stenosis ≥50% who underwent pCASL with two PLDs were included. Mean CBF and CBF subtraction images between two PLDs of MCA territories were compared in symptomatic and asymptomatic groups, respectively. Compared with the asymptomatic group, patients with symptomatic MCA stenosis had significantly lower CBF in the MCA territory of stenotic side at each PLD. The CBF of stenotic territory showed greater increase than that of normal side from PLD 1.5 to 2.5 s. The CBF of asymptomatic MCA territory increased similarly with that of symptomatic MCA territory from PLD of 1.5 to 2.5 s in stenotic side, while symptomatic patients experienced significantly slower antegrade flow. On CBF subtraction images, asymptomatic patients showed larger volume of differences between PLD of 1.5 and 2.5 s compared with those of symptomatic patients ( p = 0.037). The results suggest that more robust collateral perfusion on two-delay 3D pCASL is present in asymptomatic patients compared with symptomatic patients.

Background and purpose We investigated the baseline demographics of patients with severe unilateral atherosclerotic stenosis of the middle cerebral artery (MCA) using multimodal MRI and evaluated the haemodynamic impairments and plaque characteristics of patients who had a recurrent stroke. Materials and methods We retrospectively recruited consecutive patients with severe unilateral atherosclerotic MCA stenosis who underwent arterial spin labelling (ASL) with postlabelling delay (PLD) of 1.5 and 2.5 s, and vessel wall MRI. For each PLD, cerebral blood flow (CBF) maps were generated. Hypoperfusion volume ratio (HVR) from 2 PLD CBF was calculated. An HVR value ≥50% was considered as severe HVR. Plaque areas, plaque burden, plaque length and remodelling index were measured. Plaque enhancement at maximal lumen narrowing site were graded. Baseline clinical and imaging characteristics were compared between patients with (event+) and without (event−) 1 year ischaemic events. Results Forty-three patients (47.23±12.15 years; 28 men) were enrolled in this study. Seven patients had an HVR ≥50%. During the 1-year follow-up, 7 patients had experienced a recurrent stroke. HVR were significantly higher in the event+ than event− (53.17%±29.82% vs 16.9%±15.57%, p=0.0002), whereas no significant difference was detected in plaque areas, plaque burden, remodelling index, plaque length and plaque enhancement grade. The multivariable analysis revealed that a severe HVR was significantly associated with a recurrent stroke (Odds ratio=12.93, 95% confidence interval 1.57 to 106.24, p=0.017) after adjusted by hypertension and smoking. Conclusion HVR obtained from two PLD ASL may be a useful imaging predictor of recurrent stroke.

Background The thalamus is a key node of deep gray matter and previous studies have demonstrated that it is involved in the modulation of cognition. Purpose To investigate the volume changes of the thalamus and its subregions and altered thalamus functional connectivity patterns in Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI). Study Type Prospective. Population Thirty‐three patients with MCI ( PD‐MCI ), 36 PD patients having no cognitive impairment ( PD‐NCI ), 21 healthy controls ( HCs ). Sequence 3.0T MRI scanner; 3D T 1 ‐weighted fast spoiled gradient recalled echo ( 3D T 1 ‐FSPGR ); resting‐state fMRI Assessment Voxel‐based morphometry (VBM) was performed to calculate the volume of the thalamus and its subregions. The left and right total thalamus were considered seeds and seed‐based functional connectivity (FC) was analyzed. Additionally, correlations between volumes and cognitive performance and between FC values and cognitive performance were examined separately. Statistical Test Analysis of covariance (ANCOVA); two‐sample t ‐tests; partial correlation analysis. Results The volumes of the total thalamus (PD‐MCI vs. PD‐NCI vs. HCs: 18.39 ± 1.67 vs. 19.63 ± 1.79 vs. 19.47 ± 1.35) and its subregions were significantly reduced in PD‐MCI as compared to PD‐NCI (total thalamus: P = 0.002) and HCs (total thalamus: P = 0.012). Compared with PD‐NCI, PD‐MCI showed increased FC between the thalamus and bilateral middle cingulate cortex and left posterior cingulate cortex, and decreased FC between thalamus and the left superior occipital gyrus, left cuneus, left precuneus, and left middle occipital gyrus. Volumes of thalamus and the subregions, as well as the FC of thalamus with the identified regions, were significantly correlated ( P &lt; 0.05, FDR‐corrected) with neuropsychological scores in PD patients. Data Conclusion We noted volume loss and altered FC of thalamus in PD‐MCI patients, and these changes were correlated with global cognitive performance. Level of Evidence 2 Technical Efficiency Stage 2 J. Magn. Reson. Imaging 2020;52:1207–1215.

This study aimed to identify predictors of intracranial in-stent restenosis (ISR) after stent placement in symptomatic intracranial atherosclerotic stenosis (ICAS).The authors retrospectively collected data from consecutive patients who suffered from symptomatic ICAS and underwent successful stent placement in Beijing Tiantan hospital. Eligible patients were classified into "ISR," "indeterminate ISR," or "no-ISR" groups by follow-up digital subtraction angiography or CT angiography. A multivariate logistic regression model was used to explore the predictors of intracranial ISR after adjustments for age and sex. In addition, ISR and no-ISR patients were divided into two groups based on the strongest predictor, and the incidence of ISR, recurrent stroke, and symptomatic ISR was compared between the two groups.A total of 511 eligible patients were included in the study: 80 ISR, 232 indeterminate ISR, and 199 no-ISR patients. Elevated high-sensitivity C-reactive protein (hs-CRP; odds ratio [OR] 4.747, 95% confidence interval [CI] 2.253-10.01, p < 0.001), Mori type B and C (Mori type B vs Mori type A, OR 3.119, 95% CI 1.093-8.896, p = 0.033; Mori type C vs Mori type A, OR 4.780, 95% CI 1.244-18.37, p = 0.023), coronary artery disease (CAD; OR 2.721, 95% CI 1.192-6.212, p = 0.017), neutrophil/lymphocyte ratio (NLR; OR 1.474 95% CI 1.064-2.042, p = 0.020), residual stenosis (OR 1.050, 95% CI 1.022-1.080, p = 0.001) and concurrent intracranial tandem stenosis (OR 2.276, 95% CI 1.039-4.986, p = 0.040) synergistically contributed to the occurrence of intracranial ISR. Elevated hs-CRP (hs-CRP ≥ 3 mg/L) was the strongest predictor for ISR, and the incidence of ISR in the elevated hs-CRP group and normal hs-CRP group (hs-CRP < 3 mg/L) was 57.14% versus 21.52%, respectively, with recurrent stroke 44.64% versus 16.59%, and symptomatic ISR 41.07% versus 8.52%.Elevated hs-CRP level, NLR, residual stenosis, Mori type B and C, CAD, and concurrent intracranial tandem stenosis are the main predictors of intracranial ISR, and elevated hs-CRP is crucially associated with recurrent stroke in patients with symptomatic ICAS after intracranial stent implantation.

Focused ultrasound is a noninvasive, radiation-free and real-time therapeutic approach to treat deep-seated targets, which benefits numerous diseases otherwise requiring surgeries. Treatment efficiency is one of the key factors determining therapeutic outcomes, but improving it solely by increasing the total power can be limited by the performance of general ultrasound devices. To address this, multi-frequency therapeutic ultrasound, using additional ultrasound waves of different frequencies on top of the standard single-frequency wave, provides a promising method for treatment efficiency enhancement with limited power. Several applications and numerical works have demonstrated its superiority on treatment enhancement. This paper presents an overview of the mechanisms, implementations, applications and decisive parameters of the multi-frequency therapeutic ultrasound, which could help to pave the way for better understanding and further developing this technology in the future.

The purpose of this study was to explore the brain structural changes in type 2 diabetes and the effect of insulin on the brain using a surface-based cortical thickness analysis. High-resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI were obtained from 11 patients with type 2 diabetes before and after insulin therapy. The cortical thickness over the entire brain was calculated, and cross-sectional and longitudinal surface-based cortical thickness analyses were also performed. Regional cortical thinning was demonstrated in the middle temporal gyrus, posterior cingulate gyrus, precuneus, right lateral occipital gyrus and entorhinal cortex bilaterally for patients with type 2 diabetes mellitus compared with normal controls. Cortical thickening was seen in the middle temporal gyrus, entorhinal cortex and left inferior temporal gyrus bilaterally after patients underwent 1 year of insulin therapy. These findings suggest that insulin therapy may have recovering effects on the brain cortex in type 2 diabetes mellitus. The precise mechanism should be investigated further.

To evaluate the efficacy of 3D pseudocontinuous arterial spin labeling (3D pCASL) in the differential diagnosis between mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and acute ischemic stroke (AIS).Conventional magnetic resonance imaging (MRI) including T2 -weighted imaging (T2 WI) and diffusion-weighted imaging (DWI), and 3D pCASL perfusion data were obtained on a 3.0T MR scanner in 16 newly appearing lesions in nine patients with MELAS and 14 acute lesions in 12 patients with AIS. A postlabeling delay (PLD) time of 2025 msec was applied. The cerebral blood flow (CBF) values were measured in the central part and the peripheral part of the lesions and the CBF values were compared between MELAS and AIS patients.The lesions of both MELAS and AIS showed high signal intensity on T2 WI and demonstrated hyperintensity on DWI. Compared with the perfusion defects or hypoperfusion in all AIS, hyperperfusion was revealed in 16 acute MELAS lesions, especially in the peripheral part of the lesions. The CBF values of 16 lesions in MELAS were 11.20-73.11 ml/100g/min in the central part and 65.33-169.11 ml/100g/min in the peripheral part. The CBF values of 14 lesions in AIS were 12.32-19.94 ml/100g/min in the central part and 11.66-18.37 ml/100g/min in the peripheral part. The CBF value of the peripheral part (119.80 ± 35.41) in MELAS was significantly higher than that (14.66 ± 2.61) in AIS (P = 0.0001).The whole-brain 3D pCASL technique might be useful in differentiating MELAS from AIS.3 J. Magn. Reson. Imaging 2017;45:199-206.

To fast and accurately reconstruct human lung gas MRI from highly undersampled k-space using deep learning.The scheme was comprised of coarse-to-fine nets (C-net and F-net). Zero-filling images from retrospectively undersampled k-space at an acceleration factor of 4 were used as input for C-net, and then output intermediate results which were fed into F-net. During training, a L2 loss function was adopted in C-net, while a function that united L2 loss with proton prior knowledge was used in F-net. The 871 hyperpolarized 129 Xe pulmonary ventilation images from 72 volunteers were randomly arranged as training (90%) and testing (10%) data. Ventilation defect percentage comparisons were implemented using a paired 2-tailed Student's t-test and correlation analysis. Furthermore, prospective acquisitions were demonstrated in 5 healthy subjects and 5 asymptomatic smokers.Each image with size of 96 × 84 could be reconstructed within 31 ms (mean absolute error was 4.35% and structural similarity was 0.7558). Compared with conventional compressed sensing MRI, the mean absolute error decreased by 17.92%, but the structural similarity increased by 6.33%. For ventilation defect percentage, there were no significant differences between the fully sampled and reconstructed images through the proposed algorithm (P = 0.932), but had significant correlations (r = 0.975; P < 0.001). The prospectively undersampled results validated a good agreement with fully sampled images, with no significant differences in ventilation defect percentage but significantly higher signal-to-noise ratio values.The proposed algorithm outperformed classical undersampling methods, paving the way for future use of deep learning in real-time and accurate reconstruction of gas MRI.

Tractography-based direct targeting of the ventral intermediate nucleus (T-VIM) is a novel method that provides patient-specific VIM coordinates. This study aimed to explore the accuracy and predictive value of using T-VIM in combination with tractography and resting-state functional connectivity techniques to perform magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy as a treatment of Parkinson's disease (PD).PD patients underwent MRgFUS thalamotomy and were recruited for functional MRI scanning. A subscore of the Clinical Rating Scale for Tremor was used to evaluate tremor improvement. T-VIM and surgical VIM (S-VIM) were defined on preoperative diffusion tensor MRI and 24-hour postoperative T1-weighted imaging, respectively. The overlapping volume and center distance between S-VIM and T-VIM were measured to determine their correlations with 12-month postoperative tremor improvement. Moreover, pretherapeutic functional connectivity of T-VIM or S-VIM, based on region-of-interest connectivity and whole-brain seed-to-voxel connectivity, was measured with the resting-state functional connectivity technique to investigate their correlations with tremor improvement.All patients had excellent tremor improvement (mean [range] tremor improvement 74.82% [50.00%-94.44%]). The authors found that both overlapping volume and center distance between T-VIM and S-VIM were significantly correlated with tremor improvement (r = 0.788 and p = 0.012 for overlapping volume; r = -0.696 and p = 0.037 for center distance). Pretherapeutic functional connectivity of T-VIM with the ipsilateral sensorimotor cortex (r = 0.876 and p = 0.002), subthalamic nucleus (r = 0.700 and p = 0.036), and visual area (r = 0.911 and p = 0.001) was significantly and positively correlated with tremor improvement.T-VIM may improve the clinical application of MRgFUS thalamotomy as a treatment of PD. Pretherapeutic functional connectivity of T-VIM with the ipsilateral sensorimotor cortex, subthalamic nucleus, and visual area may predict PD tremor responses after MRgFUS thalamotomy.

Purpose This study was performed to validate the efficacy of three-dimensional pseudocontinuous arterial spin labeling (pCASL) compared with dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in distinguishing radiation-induced brain injury from glioma recurrence in patients with glioma. Methods Both 3D pCASL and DSC-PWI were performed using a 3.0 Tesla scanner in 69 patients with previously resected and irradiated glioma who displayed newly developed abnormal contrast-enhanced lesions. The included patients were classified into a radiation-induced brain injury group (n = 34) and a glioma recurrence group (n = 35) based on subsequent pathologic analysis or clinical–radiological follow-up. Lesion perfusion parameter values (CBF and nCBF on pCASL, nrCBV and nrCBF on DSC-PWI) were measured and compared between the two groups using Student’s t test. Pearson correlation analysis was performed to evaluate the correlation between pCASL (CBF and nCBF) and DSC-PWI (nrCBV and nrCBF) values in the contrast-enhanced lesions and in the perifocal edema regions. Results For the contrast-enhanced lesions, the CBF, nCBF, nrCBV, and nrCBF (29.46 ± 15.08 ml/100 g/min, 1.11 ± 0.50, 1.39 ± 1.15, and 1.30 ± 0.74) in the radiation-induced brain injury group were significantly lower than those (64.52 ± 33.92 ml/100 g/min, 2.73 ± 1.71, 3.39 ± 2.12, and 3.20 ± 1.95) in the glioma recurrence group (P < 0.001). The CBF and nCBF demonstrated strong correlation with nrCBV and nrCBF in the contrast-enhanced lesions. Conclusion Radiation-induced brain injury and glioma recurrence can be reliably distinguished using both 3D pCASL and DSC-PWI. Contrast-free 3D pCASL is a suitable alternative to DSC-PWI for long-term follow-up in glioma patients with postoperative radiotherapy.

Ischemic stroke is one of the major leading causes for long-term disability and mortality. Collateral vessels provide an alternative pathway to protect the brain against ischemic injury after arterial occlusion. Aiming at visualizing the collaterals occurring during acute ischemic stroke, an integrin αv β3 -specific Fe3 O4 -Arg-Gly-Asp (RGD) nanoprobe is prepared for magnetic resonance imaging (MRI) of the collaterals. Rat models are constructed by occluding the middle cerebral artery for imaging studies of cerebral ischemia and ischemia-reperfusion on 7.0 Tesla MRI using susceptibility-weighted imaging sequence. To show the binding specificity to the collaterals, the imaging results acquired with the Fe3 O4 -RGD nanoprobe and the Fe3 O4 mother nanoparticles, respectively, are carefully compared. In addition, an RGD blocking experiment is also carried out to support the excellent binding specificity of the Fe3 O4 -RGD nanoprobe. Following the above experiments, cerebral ischemia-reperfusion studies show the collateral dynamics upon reperfusion, which is very important for the prognosis of various revascularization therapies in the clinic. The current study has, for the first time, enabled the direct observation of collaterals in a quasi-real time fashion and further disclosed that the antegrade flow upon reperfusion dominates the blood supply of primary ischemic tissue during the early stage of infarction, which is significantly meaningful for clinical treatment of stroke.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroid (CLIPPERS) was first described in 2010. The characteristic clinical picture, radiological distribution and steroid response have been well-described in previous reports. However, the underlying pathogenesis and nosological position of CLIPPERS in the CNS require further investigation for the primary CNS lymphoma have been identified by autopsy subsequently. Here, we report a 51-year-old woman who was diagnosed with CLIPPERS but progressed to primary CNS lymphomatoid granulomatosis, which supports that CLIPPERS is not just an inflammatory CNS disorder.

The Multiple-Network Poroelastic Theory (MPET) is a numerical model to characterize the transport of multiple fluid networks in the brain, which overcomes the problem of conducting separate analyses on individual fluid compartments and losing the interactions between tissue and fluids, in addition to the interaction between the different fluids themselves. In this paper, the blood perfusion results from MPET modeling are partially validated using cerebral blood flow (CBF) data obtained from arterial spin labeling (ASL) magnetic resonance imaging (MRI), which uses arterial blood water as an endogenous tracer to measure CBF. Two subjects-one healthy control and one patient with unilateral middle cerebral artery (MCA) stenosis are included in the validation test. The comparison shows several similarities between CBF data from ASL and blood perfusion results from MPET modeling, such as higher blood perfusion in the gray matter than in the white matter, higher perfusion in the periventricular region for both the healthy control and the patient, and asymmetric distribution of blood perfusion for the patient. Although the partial validation is mainly conducted in a qualitative way, it is one important step toward the full validation of the MPET model, which has the potential to be used as a testing bed for hypotheses and new theories in neuroscience research.

MRgFUS has just been made available for the 1.7 million Parkinson's disease patients in China. Despite its non-invasive and rapid therapeutic advantages for involuntary tremor, some concerns have emerged about outcomes variability, non-specificity, and side-effects, as little is known about its impact on the long-term plasticity of brain structure. We sought to dissect the characteristics of long-term changes in brain structure caused by MRgFUS lesion and explored potential biological mechanisms. One-year multimodal imaging follow-ups were conducted for nine tremor-dominant Parkinson's disease patients undergoing unilateral MRgFUS thalamotomy. A structural connectivity map was generated for each patient to analyze dynamic changes in brain structure. The human brain transcriptome was extracted and spatially registered for connectivity vulnerability. Genetic functional enrichment analysis was performed and further clarified using in vivo emission computed tomography data. MRgFUS not only abolished tremors but also significantly disrupted the brain network topology. Network-based statistics identified a U-shape MRgFUS-sensitive subnetwork reflective of hand tremor recovery and surgical process, accompanied by relevant cerebral blood flow and gray matter alteration. Using human brain gene expression data, we observed that dopaminergic signatures were responsible for the preferential vulnerability associated with these architectural alterations. Additional PET/SPECT data not only validated these gene signatures, but also suggested that structural alteration was significantly correlated with D1 and D2 receptors, DAT, and F-DOPA measures. There was a long-term dynamic loop between structural alteration and dopaminergic signature for MRgFUS thalamotomy, which may be closely related to the long-term improvements in clinical tremor.

Metal organic frameworks with tunable pore structures are able to provide varied chemical environments for hyperpolarized¹²⁹Xe atom hosting, which results in distinguishing magnetic resonance signals, and stains ultra-sensitive magnetic resonance imaging (MRI) with diverse colors.

Background Magnetic resonance‐guided focused ultrasound (MRgFUS) thalamotomy has been implemented as a therapeutic alternative for the treatment of drug‐refractory essential tremor (ET). However, its impact on the brain structural network is still unclear. Purpose To investigate both global and local alterations of the white matter (WM) connectivity network in ET after MRgFUS thalamotomy. Study Type Retrospective. Subjects Twenty‐seven ET patients (61 ± 11 years, 19 males) with MRgFUS thalamotomy and 28 healthy controls (HC) (61 ± 11 years, 20 males) were recruited for comparison. Field Strength/Sequence A 3 T/single shell diffusion tensor imaging by using spin‐echo‐based echo‐planar imaging, three‐dimensional T1 weighted imaging by using gradient‐echo‐based sequence. Assessment Patients were undergoing MRgFUS thalamotomy and their clinical data were collected from pre‐operation to 6‐month post‐operation. Network topological metrics, including rich‐club organization, small‐world, and efficiency properties were calculated. Correlation between the topological metrics and tremor scores in ET groups was also calculated to assess the role of neural remodeling in the brain. Statistical Tests Two‐sample independent t ‐tests, chi‐squared test, ANOVA, Bonferroni test, and Spearman's correlation. Statistical significance was set at P &lt; 0.05. Results For ET patients, the strength of rich‐club connection and clustering coefficient significantly increased vs. characteristic path length decreased at 6‐month post‐operation compared with pre‐operation. The distribution pattern of rich‐club regions was different in ET groups. Specifically, the order of the rich‐club regions was changed according to the network degree value after MRgFUS thalamotomy. Moreover, the altered nodal efficiency in the right temporal pole of the superior temporal gyrus ( R = 0.434–0.596) and right putamen ( R = 0.413–0.436) was positively correlated with different tremor improvement. Data Conclusion These findings might improve understanding of treatment‐induced modulation from a network perspective and may work as an objective marker in the assessment of ET tremor control with MRgFUS thalamotomy. Level of Evidence 3 Technical Efficacy Stage 4

Background Iodinated contrast agents (ICAs), which are widely used in CT angiography (CTA), may cause adverse effects in humans, and their use is time-consuming and costly. Purpose To develop an ICA-free deep learning imaging model for synthesizing CTA-like images and to assess quantitative and qualitative image quality as well as the diagnostic accuracy of synthetic CTA (Syn-CTA) images. Materials and Methods A generative adversarial network (GAN)–based CTA imaging model was trained, validated, and tested on retrospectively collected pairs of noncontrast CT and CTA images of the neck and abdomen from January 2017 to June 2022, and further validated on an external data set. Syn-CTA image quality was evaluated using quantitative metrics. In addition, two senior radiologists scored the visual quality on a three-point scale (3 = good) and determined the vascular diagnosis. The validity of Syn-CTA images was evaluated by comparing the visual quality scores and diagnostic accuracy of aortic and carotid artery disease between Syn-CTA and real CTA scans. Results CT scans from 1749 patients (median age, 60 years [IQR, 50–68 years]; 1057 male patients) were included in the internal data set: 1137 for training, 400 for validation, and 212 for testing. The external validation set comprised CT scans from 42 patients (median age, 67 years [IQR, 59–74 years]; 37 male patients). Syn-CTA images had high similarity to real CTA images (normalized mean absolute error, 0.011 and 0.013 for internal and external test set, respectively; peak signal-to-noise ratio, 32.07 dB and 31.58 dB; structural similarity, 0.919 and 0.906). The visual quality of Syn-CTA and real CTA images was comparable (internal test set, P = .35; external validation set, P > .99). Syn-CTA showed reasonable to good diagnostic accuracy for vascular diseases (internal test set: accuracy = 94%, macro F1 score = 91%; external validation set: accuracy = 86%, macro F1 score = 83%). Conclusion A GAN-based model that synthesizes neck and abdominal CTA-like images without the use of ICAs shows promise in vascular diagnosis compared with real CTA images. Clinical trial registration no. NCT05471869 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhang and Turkbey in this issue.

ABSTRACT OBJECTIVE Papillary glioneuronal tumor (PGNT) was newly classified as a Grade I neuronal-glial tumor by 2007 revision of the World Health Organization (WHO) classification of tumor of central nervous system (CNS) because of its characteristic pseudopapillae and diphase differentiation features. Previous literature has laid particular emphasis on pathology manifestations, and radiological features were only briefly mentioned. The purpose of this study was to describe magnetic resonance imaging (MRI) features through reporting 2 cases of PGNT and literature review. METHODS MRI findings and pathology features in 2 cases of PGNT were reported and the literature was reviewed. RESULTS Both patients were confirmed as PGNT by surgery and pathology. Seizure was the main clinical manifestation. Histopathological examination revealed characteristic pseudopapillary structure with astrocytes and neurons. Both lesions were located in the temporal lobe, and one case was closely related with the lateral ventricle. MRI showed cystic-solid mass or cystic lesion with mural nodule. The solid component enhanced strikingly after contrast agent administration. CONCLUSIONS MRI findings of PGNT present certain characteristics. Most cases showed cystic mass with mural nodule and periventricular location was common. Although radiological findings can provide some evidence for this newly established tumor entity, differential diagnosis is still needed.

To investigate the hemodynamic changes of normal-appearing white matter (NAWM) in hypertension using the 3D pseudocontinuous arterial spin labeling (pCASL) technique.Seventy-three subjects, including a patient group (n = 41; 30 males; age = 47.7 ± 8.3 years; test-time blood pressure [BP] = 155 ± 23/98 ± 11 mmHg) and an age-matched control group (n = 32; 14 males; age = 46 ± 8.3 years; test-time BP = 117 ± 8/76 ± 10 mmHg), were recruited and scanned on a 3.0T magnetic resonance imaging (MRI) system using routine MRI sequences and 3D pCASL sequence. The routine MRI sequences were used to further define the NAWM. The cerebral blood flow (CBF) values in various regions of interest (ROIs) were extracted. One-way analysis of variance (ANOVA) and unpaired t-test were performed to evaluate the significance of the intergroup difference in CBF modifications.Compared to healthy volunteers, CBF values in global gray matter (GM) and various NAWM regions were found to be lower (P < 0.05) in hypertensive patients, except for genu of corpus callosum (CC), cingulate gyrus, amygdala, pallidum, putamen, and thalamus (P > 0.05). Furthermore, compared to the control group, mild hypertension showed significantly reduced CBF in various ROIs (P < 0.05), but no intergroup differences in GM, R anterior horn of periventricular WM, and genu of CC (P > 0.05), while moderate hypertension showed reduced CBF in all ROIs (P < 0.05). However, it was observed that, between mild and moderate hypertensive patients, there were no statistically significant difference in CBF values except for genu of CC (P < 0.05).3D pCASL has the ability to detect subtle hemodynamic abnormalities in NAWM regions at relatively early stages of hypertension. The observed decreases in CBF in these regions may suggest an increased risk of cerebral small vessel diseases.

Background Precise diagnosis and early appropriate treatment are of importance to reduce neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) morbidity. Distinguishing NMOSD from MS based on clinical manifestations and neuroimaging remains challenging. Purpose To investigate radiomic signatures as potential imaging biomarkers for distinguishing NMOSD from MS, and to develop and validate a diagnostic radiomic‐signature‐based nomogram for individualized disease discrimination. Study Type Retrospective, cross‐sectional study. Subjects Seventy‐seven NMOSD patients and 73 MS patients. Field Strength/Sequence 3T/T 2 ‐weighted imaging. Assessment Eighty‐eight patients and 62 patients were respectively enrolled in the primary and validation cohorts. Quantitative radiomic features were automatically extracted from lesioned regions on T 2 ‐weighted imaging. A least absolute shrinkage and selection operator analysis was used to reduce the dimensionality of features. Finally, we constructed a radiomic nomogram for disease discrimination. Statistical Tests Features were compared using the Mann–Whitney U ‐test with a nonnormal distribution. We depicted the nomogram on the basis of the results of the logistic regression using the rms package in R. The Hmisc package was used to investigate the performance of the nomogram via Harrell's C‐index. Results A total of 273 quantitative radiomic features were extracted from lesions. A multivariable analysis selected 11 radiomic features and five clinical features to be included in the model. The radiomic signature ( P &lt; 0.001 for both the primary and validation cohorts) showed good potential for building a classification model for disease discrimination. The area under the receiver operating characteristic curve was 0.9880 for the training cohort and 0.9363 for the validation cohort. The nomogram exhibited good discrimination, a concordance index of 0.9363, and good calibration in the primary cohort. The nomogram showed similar discrimination, concordance (0.9940), and calibration in the validation cohort. Data Conclusion The diagnostic radiomic‐signature‐based nomogram has potential utility for individualized disease discrimination of NMOSD from MS in clinical practice. Level of Evidence : 4 Technical Efficacy : Stage 2 J. Magn. Reson. Imaging 2019;49:1113–1121.

An optimal restoration strategy for supply chain networks can efficiently schedule the repair activities under resource limits. However, a wide range of previous studies solve this problem from the perspective of cost-effectiveness instead of a resilient manner. This research formulates the problem as a network maximum-resilience decision. We develop two metrics to measure the resilience of the supply chain networks, i.e., the resilience of cumulative performance loss and the resilience of restoration rapidity. Then, we propose a bi-objective nonlinear programming model, which aims to maximize the network resilience under the budget and manpower constraints. A modified simulated annealing algorithm is employed to solve the model. Finally, a testing supply chain network is utilized to illustrate the effectiveness of the proposed method framework. The results show that the optimal restoration schedule generated by the proposed model is a tradeoff between the cumulative performance loss and the restoration rapidity. Additionally, the sensitivity analysis of parameters indicates that decision-maker’s preference, tolerance factor of delivery time, number of work crews, and availability of budget all have significant impacts on the restoration schedule.

To visualize and quantitatively assess regional lung function of survivors of COVID-19 who were hospitalized using pulmonary free-breathing 1H MRI.A total of 12 healthy volunteers and 27 COVID-19 survivors (62.4 ± 8.1 days between infection and image acquisition) were recruited in this prospective study and performed chest 1H MRI acquisitions with free tidal breathing. Then, conventional Fourier decomposition ventilation (FD-V) and global fractional ventilation (FVGlobal) were analyzed. Besides, a modified PREFUL (mPREFUL) method was developed to adapt to COVID-19 survivors and generate dynamic ventilation maps and parameters. All the ventilation maps and parameters were analyzed using Student's t-test. Pearson's correlation and a Bland-Altman plot between FVGlobal and mPREFUL were analyzed.There was no significant difference between COVID-19 and healthy groups regarding a static FD-V map (0.47 ± 0.12 vs 0.42 ± 0.08; p = .233). However, mPREFUL demonstrated lots of regional high ventilation areas (high ventilation percentage (HVP): 23.7% ± 10.6%) existed in survivors. This regional heterogeneity (i.e., HVP) in survivors was significantly higher than in healthy volunteers (p = .003). The survivors breathed deeper (flow-volume loop: 5375 ± 3978 vs 1688 ± 789; p = .005), and breathed more air in respiratory cycle (total amount: 62.6 ± 19.3 vs 37.3 ± 9.9; p < .001). Besides, mPREFUL showed both good Pearson's correlation (r = 0.74; p < .001) and Bland-Altman consistency (mean bias = -0.01) with FVGlobal.Dynamic ventilation imaging using pulmonary free-breathing 1H MRI found regional abnormity of dynamic ventilation function in COVID-19 survivors.• Pulmonary free-breathing1H MRI was used to visualize and quantitatively assess regional lung ventilation function of COVID-19 survivors. • Dynamic ventilation maps generated from 1H MRI were more sensitive to distinguish the COVID-19 and healthy groups (total air amount: 62.6 ± 19.3 vs 37.3 ± 9.9; p < .001), compared with static ventilation maps (FD-V value: 0.47 ± 0.12 vs 0.42 ± 0.08; p = .233). • COVID-19 survivors had larger regional heterogeneity (high ventilation percentage: 23.7% ± 10.6% vs 13.1% ± 7.9%; p = .003), and breathed deeper (flow-volume loop: 5375 ± 3978 vs 1688 ± 789; p = .005) than healthy volunteers.

Although the lungs are the primary organ involved, increasing evidence supports the neuroinvasive potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study investigates the potential relationship between coronavirus disease (COVID-19)-related deterioration of brain structure and the degree of damage to lung function. Nine COVID-19 patients were recruited in critical condition from Jin Yin-tan Hospital (Wuhan, China) who had been discharged between 4 February and 27 February 2020. The demographic, clinical, treatment, and laboratory data were extracted from the electronic medical records. All patients underwent chest CT imaging, 129Xe gas lung MRI, and 1H brain MRI. Four of the patients were followed up for 8 months. After nearly 12 months of recovery, we found no significant difference in lung ventilation defect percentage (VDP) between the COVID-19 group and the healthy group (3.8 ± 2.1% versus 3.7 ± 2.2%) using 129Xe MRI, and several lung-function-related parameters—such as gas–blood exchange time (T)—showed improvement (42.2 ms versus 32.5 ms). Combined with 1H brain MRI, we found that the change in gray matter volume (GMV) was strongly related to the degree of pulmonary function recovery—the greater the increase in GMV, the higher degree of pulmonary function damage.

Parkinson's disease (PD) is a common, progressive, and incurable neurodegenerative disease. Pharmacological treatment is the first-line therapy for PD, including carbidopa-levodopa, dopamine agonists. However, some patients respond poorly to medication. For these patients, functional neurosurgical treatment is an important option. Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel, minimally invasive surgical option for patients refractory to drugs. Currently, several important anatomical structures can be targeted by MRgFUS in the treatment of PD. However, there is no uniform standard for target selection. This review summarizes the clinical studies on MRgFUS for PD, focusing on the relationship between different treatment targets and the relieved symptoms, to help clinicians determine the ideal therapeutic target for individual patients. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 4.

MRI-guided focused ultrasound (MRgFUS) thalamotomy is a novel, effective, and non-invasive treatment for essential tremor (ET). However, the network mediating MRgFUS in treating ET is not precisely known. This study aimed to identify the disease-specific network associated with the therapeutic effects of MRgFUS thalamotomy on ET and investigate its regional characteristics and genetic signatures to gain insights into the neurobiological mechanism of ET and MRgFUS thalamotomy. Twenty-four ET patients treated with MRgFUS thalamotomy underwent resting-state functional MRI at baseline and postoperative 6 months to measure the fractional amplitude of low-frequency fluctuation (fALFF). Ordinal trends canonical variates analysis (OrT/CVA) was performed on the within-subject fALFF data to identify the ET-related network. Genetic functional enrichment analysis was conducted to study the genetic signatures of this ET-related network using brain-wide gene expression data. OrT/CVA analysis revealed a significant ET-related network for which subject expression showed consistent increases after surgery. The treatment-induced increases in subject expression were significantly correlated with concurrent tremor improvement. This network was characterized by increased activity in the sensorimotor cortex and decreased activity in the posterior cingulate cortex. It was correlated with an expression map of a weighted combination genes enriched for mitochondria relevant ontology terms. This study demonstrates that the therapeutic effects of MRgFUS thalamotomy on ET are associated with modulating a distinct ET-related network which may be driven by mitochondria relevant neurobiological mechanism. Quantification of treatment-induced modulation on the ET-related network can provide an objective marker for evaluating the efficacy of MRgFUS thalamotomy.

In this study, we focus on the effectiveness of adversarial attacks on the scene segmentation function of autonomous driving systems (ADS). We explore both offensive as well as defensive aspects of the attacks in order to gain a comprehensive understanding of the effectiveness of adversarial attacks with respect to semantic segmentation. More specifically, in the offensive aspect, we improved the existing adversarial attack methodology with the idea of momentum. The adversarial examples generated by the improved method show higher transferability in both targeted as well as untargeted attacks. In the defensive aspect, we implemented and analyzed five different mitigation techniques proven to be effective in defending against adversarial attacks in image classification tasks. The image transformation methods such as JPEG compression and low pass filtering showed good performance when used against adversarial attacks in a white box setting.

The role of mobile cameras increased dramatically over the past few years, leading to more and more research in automatic image quality enhancement and RAW photo processing. In this Mobile AI challenge, the target was to develop an efficient end-to-end AI-based image signal processing (ISP) pipeline replacing the standard mobile ISPs that can run on modern smartphone GPUs using TensorFlow Lite. The participants were provided with a large-scale Fujifilm UltraISP dataset consisting of thousands of paired photos captured with a normal mobile camera sensor and a professional 102MP medium-format FujiFilm GFX100 camera. The runtime of the resulting models was evaluated on the Snapdragon's 8 Gen 1 GPU that provides excellent acceleration results for the majority of common deep learning ops. The proposed solutions are compatible with all recent mobile GPUs, being able to process Full HD photos in less than 20–50 ms while achieving high fidelity results. A detailed description of all models developed in this challenge is provided in this paper.

Tinnitus is frequently found in patients with vestibular schwannoma (VS), but its underlying mechanisms are currently unclear.Both preoperative (VS pre ) and postoperative (VS post ) functional MR images were collected from 32 patients with unilateral VS and matched healthy controls (HCs). Connectome gradients were generated for the identification of altered regions and perturbed gradient distances. Tinnitus measurements were conducted for predictive analysis with neuroimaging-genetic integration analysis.There were 56.25% of preoperative patients and 65.63% of postoperative patients suffering from ipsilateral tinnitus, respectively. No relevant factors were identified including basic demographics info, hearing performances, tumor features, and surgical approaches. Functional gradient analysis confirmed atypical functional features of visual areas in VS pre were rescued after tumor resection, while the gradient performance in the postcentral gyrus continues to maintain (VS post vs. HC : P = 0.016). The gradient features of the postcentral gyrus were not only significantly decreased in patients with tinnitus (PFDR = 0.022), but also significantly correlated with tinnitus handicap inventory (THI) score (r = -0.30, P = 0.013), THI level (r = -0.31, P = 0.010), and visual analog scale (VAS) rating (r = -0.31, P = 0.0093), which could be used to predict VAS rating in the linear model. Neuropathophysiological features linked to the tinnitus gradient framework were linked to Ribosome dysfunction and oxidative phosphorylation.Altered functional plasticity in the central nervous system is involved in the maintenance of VS tinnitus.

Abstract Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel and minimally invasive technology. Since the US Food and Drug Administration approved unilateral ventral intermediate nucleus-MRgFUS for medication-refractory essential tremor in 2016, studies on new indications, such as Parkinson's disease (PD), psychiatric diseases, and brain tumors, have been on the rise, and MRgFUS has become a promising method to treat such neurological diseases. Currently, as the second most common degenerative disease, PD is a research hotspot in the field of MRgFUS. The actions of MRgFUS on the brain range from thermoablation, blood-brain barrier (BBB) opening, to neuromodulation. Intensity is a key determinant of ultrasound actions. Generally, high intensity can be used to precisely thermoablate brain targets, whereas low intensity can be used as molecular therapies to modulate neuronal activity and open the BBB in conjunction with injected microbubbles. Here, we aimed to summarize advances in the application of MRgFUS for the treatment of PD, with a focus on thermal ablation, BBB opening, and neuromodulation, in the hope of informing clinicians of current applications.

Global brain health has gained increasing attention recently. Imaging markers of brain frailty have been related to functional outcomes in previous studies on anterior circulation; however, little data are available on imaging markers and posterior circulation.To investigate the impact of brain frailty on functional outcomes in patients with acute perforating artery infarction (PAI) of the posterior circulation.Prospective.One hundred patients (60.78 ± 9.51 years, 72% men) with acute posterior circulation PAI (determined by diffusion-weighted magnetic resonance imaging (MRI)/time-of-flight MR angiography).T1- and T2-weighted fast spin echo, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted echo planar, gradient echo (susceptibility-weight imaging), and 3D time-of-flight MR angiography sequences at 3.0 T.Periventricular and deep white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS) in the basal ganglia and centrum semiovale area, lacunes, cerebral microbleeds (CMB), and total brain frailty score by calculating the above imaging characters were rated visually by three radiologists with 9, 10, and 11 years of experience and one neuroradiologist with 12. Infarction volume was assessed using baseline diffusion-weighted imaging (DWI) data obtained within 24 hours of symptom onset. A modified Rankin Scale (mRS) score >1 on day 90 defined an adverse functional outcome. Associations between the imaging markers of brain frailty and functional outcomes were assessed.Fisher's exact test, Mann-Whitney U test, and multivariable binary logistic regression. A P value <0.05 was considered statistically significant.Adverse prognoses (mRS > 1) were observed in 34 (34%) patients. Infarction volume, periventricular WMH, deep WMH, basal ganglia EPVS, CMB, and the brain frailty score were significantly associated with adverse functional outcomes. An increased brain frailty score was significantly associated with unfavorable mRS score on day 90 (odds ratio 1.773, 95% confidence interval 1.237-2.541).Advanced MRI imaging markers of brain frailty, individually or combined as a total brain frailty score, were associated with worse functional outcomes after acute posterior circulation PAI.3 TECHNICAL EFFICACY: Stage 3.

JOURNAL/nrgr/04.03/01300535-202409000-00041/figure1/v/2024-01-16T183250Z/r/image-tiff The safety and effectiveness of magnetic resonance-guided focused ultrasound thalamotomy has been broadly established and validated for the treatment of essential tremor. In 2018, the first magnetic resonance-guided focused ultrasound system in Chinese mainland was installed at the First Medical Center of the PLA General Hospital. This prospective, single center, open-label, single-arm study was part of a worldwide prospective multicenter clinical trial (ClinicalTrials.gov Identifier: NCT03253991) conducted to confirm the safety and efficacy of magnetic resonance-guided focused ultrasound for treating essential tremor in the local population. From 2019 to 2020, 10 patients with medication refractory essential tremor were recruited into this open-label, single arm study. The treatment efficacy was determined using the Clinical Rating Scale for Tremor. Safety was evaluated according to the incidence and severity of adverse events. All of the subjects underwent a unilateral thalamotomy targeting the ventral intermediate nucleus. At the baseline assessment, the estimated marginal mean of the Clinical Rating Scale for Tremor total score was 58.3 ± 3.6, and this improved after treatment to 23.1 ± 6.4 at a 12-month follow-up assessment. A total of 50 adverse events were recorded, and 2 were defined as serious. The most common intraoperative adverse events were nausea and headache. The most frequent postoperative adverse events were paresthesia and equilibrium disorder. Most of the adverse events were mild and usually disappeared within a few days. Our findings suggest that magnetic resonance-guided focused ultrasound for the treatment of essential tremor is effective, with a good safety profile, for patients in Chinese mainland.

The mechanism underlying tinnitus remains unclear, and when it coexists with vestibular schwannoma (VS), it can significantly diminish the quality of life for affected patients. This study aimed to determine the correlation between preoperative clinical characteristics of VS, postoperative changes in brain function, and tinnitus in patients with VS through a cohort study.We collected data from 80 patients with VS preoperatively and 28 patients with VS preoperatively and postoperatively, and recruited 28 healthy controls. We used Chi-squared tests and unpaired t-tests to identify clinical characteristics with a significant preoperative effect. We used paired t-tests to identify brain regions where patients demonstrated significant changes in amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) postoperatively. Tinnitus severity was evaluated using the Tinnitus Handicap Inventory (THI) and Visual Analogue Scale (VAS). Pearson correlation coefficients were applied to assess the relationship between the changes in ALFF and ReHo and the changes in THI and VAS scores postoperatively. We also conducted seed- and region of interest (ROI)-based functional connectivity (FC) analyses.Before surgery, patients with VS with tinnitus (n=49) had smaller tumors (t=3.293; P<0.001), more solid tumor (χ2=4.559; P=0.033), and less extrusion into the cerebellum brain stem (χ2=10.345; P=0.001) than those without tinnitus (n=31). After surgery, the 28 patients with VS showed a significant reduction in ALFF in the left Cerebellum_Crus2 (a lobule in the cerebellum anatomy) (ROI 1) and a significant reduction in ReHo in the left Cerebellum_Crus1 (a lobule in the cerebellum anatomy) (ROI 2) and the right precuneus (ROI 3). Conversely, ReHo was significantly increased in the right precentral gyrus (ROI 4) [cluster-level P value family-wise error (PFWE) <0.05]. The changes in ALFF values were negatively correlated with changes in the VAS score (r=-0.32; P<0.05). The FC strengths of patients between ROI 2 and the left and right posterior cingulate gyrus were significantly decreased postoperatively [false discovery rate (FDR) correction; P<0.05].Preoperative tinnitus in patients with VS may be influenced by tumor characteristics. The functional activities of brain regions are possibly altered postoperatively, which may be involved in the maintenance of postoperative tinnitus. Notably, the changes in ALFF are correlated with tinnitus.

We aim to investigate whether cerebral small vessel disease (cSVD) imaging markers correlate with deep medullary vein (DMV) damage in small vessel occlusion acute ischemic stroke (SVO-AIS) patients.The DMV was divided into six segments according to the regional anatomy. The total DMV score (0-18) was calculated based on segmental continuity and visibility. The damage of DMV was grouped according to the quartiles of the total DMV score. Neuroimaging biomarkers of cSVD including white matter hyperintensity (WMH), cerebral microbleed (CMB), perivascular space (PVS), and lacune were identified. The cSVD score were further analyzed.We included 229 SVO-AIS patients, the mean age was 63.7 ± 23.1 years, the median NIHSS score was 3 (IQR, 2-6). In the severe DMV burden group (the 4th quartile), the NIHSS score grade (6 (3-9)) was significantly higher than other groups (p < 0.01). The grade scores for basal ganglia PVS (BG-PVS) were positively correlated with the degree of DMV (R = 0.67, p < 0.01), rather than centrum semivole PVS (CS-PVS) (R = 0.17, p = 0.1). In multivariate analysis, high CMB burden (adjusted odds ratio [aOR], 25.38; 95% confidence interval [CI], 1.87-345.23) was associated with severe DMV scores. In addition, BG-PVS was related to severe DMV burden in a dose-dependent manner: when BG-PVS score was 3 and 4, the aORs of severe DMV burden were 18.5 and 12.19, respectively.The DMV impairment was associated with the severity of cSVD, which suggests that DMV burden may be used for risk stratification in SVO-AIS patients.The DMV damage score, based on the association between small vessel disease and the deep medullary veins impairment, is a potential new imaging biomarker for the prognosis of small vessel occlusion acute ischemic stroke, with clinical management implications.• The damage to the deep medullary vein may be one mechanism of cerebral small vessel disease. • Severe burden of the basal ganglia perivascular space and cerebral microbleed is closely associated with significant impairment to the deep medullary vein. • The deep medullary vein damage score may reflect a risk of added vascular damage in small vessel occlusion acute ischemic stroke patients.

Abstract Background There were variable differences and declines in efficacy of magnetic resonance guided focused ultrasound (MRgFUS) thalamotomy, but whether the clinical status of these patients was involved was still unknown. Methods We retrospectively reviewed the tremor symptoms and clinical variables (at hospitalization) of 59 essential tremor (ET) patients subjected with MRgFUS thalamotomy. Patients were categorized by the short-term tremor relieve, tremor recurrence within 12 months and long-term maintenance outcome. Multivariate logistic regression was used to screen independent factors and construct the nomogram. Additional harmaline-induced ET model in male ICR mice were employed, we evaluated the possible anti-tremor effects of fibrinogen knock-out. Results MRgFUS thalamotomy resulted in significant tremor relieve, multivariate analysis suggested fibrinogen (OR = 0.182, 95% CI = 0.042-0.796,) and monocyte count (OR = 0, 95% CI = 0-0.001) were independently associated with better short-term tremor relieve (&gt;75%) at 1-month postoperatively. A total of nine ET patients (15.254%) experienced significant tremor recurrence. Admission systolic blood pressure (OR = 1.013, 95% CI = 1.010-1.062), hypertension comorbidity (OR = 2.163, 95% CI = 1.412-53.565) and fibrinogen (OR = 1.620, 95% CI = 1.047-24.376) independently contributed to tremor recurrence. There were 15 ET patients (25.424%) sustained long-term and effective tremor control. Only admission systolic blood pressure was the independent prognostic factor (OR = 0.880, 95% CI = 0.785-0.987) for this favorable outcome. The nomograms were established for better tremor relieve and tremor recurrence and have excellent performance as the AUCs were 0.829 and 0.853 (bootstrap repetition = 1000). Finally, FGB knock-out significantly suppressed harmaline-induced tremor in vivo ( P &lt; 0.001). Conclusion Fibrinogen and hypertension are key factors associated with tremor relieve and recurrence in the ET patients subjected with MRgFUS thalamotomy.

Magnetic resonance-guided focused ultrasound (MRgFUS) is a non-invasive technique for neuroregulation that offers several advantages, including non-invasiveness, no need for general anesthesia requirement, real-time target localization, and real-time temperature monitoring. Currently, the U.S. Food and Drug Administration has approved this technology for the treatment of essential tremor and Parkinson's disease, and its indications are continually expanding to encompass various intracranial diseases. In this article, we summarize clinical trials of high-intensity FUS in the treatment of intracranial diseases. Next, we introduce the preclinical and clinical studies on low-intensity FUS-induced blood-brain barrier opening and neuromodulation. Finally, we discuss the challenges and future directions of this technology. This review aims to guide future clinical trials and provide new perspectives for investigating the neural mechanisms of MRgFUS.

BackgroundThe development of artificial intelligence (AI)–based medical systems heavily relies on the collection and annotation of sufficient data containing disorders. However, the preparation of data with complete disorder types and adequate annotations presents a significant challenge, limiting the diagnostic capabilities of existing AI-based medical systems. This study introduces a novel AI-based system that accurately detects a broad spectrum of disorders without requiring any disorder-containing data. MethodsWe obtained a training dataset of 21,429 disorder-free head computed tomography (CT) scans and proposed a learning algorithm called inverse supervised learning (ISL). This algorithm learns and understands disorder-free samples instead of disorder-contained ones, enabling the identification of all types of disorders. We also developed a diagnosis and visualization software for clinical usage on the basis of the system's ability to provide visually understandable clues. ResultsThe system achieved area under the receiver operating characteristic curve (AUC) values of 0.883, 0.868, and 0.866 on retrospective (127 disorder types, 9967 scans), prospective (117 disorder types, 3054 scans), and cross-center (46 disorder types, 554 scans) datasets, respectively. These results demonstrate that the system can detect far more disorder types than previous AI-based systems. Furthermore, the ISL-based systems achieved AUC values of 0.893 and 0.895 on pulmonary CT and retinal optical coherence tomography, respectively, demonstrating that ISL can generalize well to nonhead and non-CT images. ConclusionsOur novel AI-based system utilizing ISL can accurately and broadly detect disorders without requiring disorder-containing data. This system not only outperforms previous AI-based systems in terms of disorder detection but also provides visually understandable clues, enhancing its clinical utility. The successful application of ISL to nonhead and non-CT images further demonstrates its potential for broad-spectrum medical applications. (Funded by the National Key R&D Program of China and the National Natural Science Foundation of China.)

MR-guided focused ultrasound (MRgFUS) thalamotomy is a novel and effective treatment for medication-refractory tremor in essential tremor (ET), but how the brain responds to this deliberate lesion is not clear.The current study aimed to evaluate the immediate and longitudinal alterations of functional networks after MRgFUS thalamotomy.We retrospectively obtained preoperative and postoperative 30-day, 90-day, and 180-day data of 31 ET patients subjected with MRgFUS thalamotomy from 2018 to 2020. Their archived resting-state functional MRI data were used for functional network comparison as well as graph-theory metrics analysis. Both partial least squares (PLS) regression and linear regression were conducted to associate functional features to tremor symptoms.MRgFUS thalamotomy dramatically abolished tremors, while global functional network only sustained immediate fluctuation within one week after the surgery. Network-based statistics have identified a long-term enhanced corticostriatal subnetwork by comparison between 180-day and preoperative data (P = 0.019). Within this subnetwork, network degree, global efficiency and transitivity were significantly recovered in ET patients right after MRgFUS thalamotomy compared to the pre-operative timepoint (P < 0.05), as well as hemisphere lateralization (P < 0.001). The PLS main component significantly accounted for 33.68 % and 34.16 % of the total variances of hand tremor score and clinical rating scale for tremor (CRST)-total score (P = 0.037 and 0.027). Network transitivity of this subnetwork could serve as a reliable biomarker for hand tremor score control prediction at 180-day after the surgery (β = 2.94, P = 0.03).MRgFUS thalamotomy promoted corticostriatal connectivity activation correlated with tremor improvement in ET patient after MRgFUS thalamotomy.

为解决基于深度卷积神经网络进行SAR舰船检测网络训练过程中数据获取、数据标注等问题,本文提出一种生成式知识迁移的SAR舰船检测框架,该框架由生成式知识迁移网络和舰船检测网络两部分组成。通过知识迁移网络生成与有标注的光学遥感图像空间分布一致且包含SAR图像特征的带标注模拟图像;使用所生成的带标注模拟图像,进一步优化舰船检测网络,以提高基于深度卷积神经网络的舰船检测的泛化性能。SAR-Ship-Detection-Datasets(SSDD)和AIR-SARShip-1.0两个公开数据集上的实验结果表明,该框架有效提高了在仅包含少量标注SAR图像样本情况下的舰船目标检测效果,可显著降低舰船在复杂背景图像中漏检和误检的概率。

Germinomas originating from the basal ganglia (BG) are rare. Early diagnosis is important for favorable prognosis, but it is difficult due to the slow clinical course and subtle changes on neuroimaging. The purpose of this study was to evaluate the usefulness of susceptibility-weighted imaging (SWI) in the diagnosis of early BG germinoma.From 2006 to 2008, 6 BG germinomas were diagnosed in children at our institution by pathology. Conventional MR imaging and SWI were available in all cases. Clinical, neuroradiologic, and follow-up features were retrospectively studied.Three cases were classified as early BG germinomas. Conventional MR imaging demonstrated that the tumor size was <10 mm in the largest diameter. The tumors were invisible or showed slight hyperintensity on T1-weighted images (T1WI) and patchy slight hyperintensity on T2-weighted images (T2WI) without mass effect or enhancement. On SWI, the tumors appeared as obvious hypointensity in the globus pallidus and putamen, and the size was larger than that on conventional T1WI and T2WI. The other 3 cases with tumor size >10 mm in largest diameter were classified as late BG germinomas, with tumor necrosis, fluid-fluid levels, and perifocal edema, including 1 case with subependymal spread. On SWI, only the solid portion of the tumors showed hypointensity. No recurrence was noted on follow-up.SWI appears to be more sensitive in detecting early BG germinomas than conventional MR imaging. This capability may prove to be useful in future attempts to characterize early BG germinomas.

To investigate the conventional magnetic resonance (MR) findings of cervical spinal cord, to explore the possible changes on diffusion tensor imaging (DTI) in patients with amyotrophic lateral sclerosis (ALS), and to assess the correlations between the changes on DTI and clinical parameters in patients with ALS.Conventional MR imaging (MRI) and DTI in 24 patients with ALS and 16 age-matched control subjects were obtained. On axial planes, regions of interest (ROIs) were marked in bilateral spinothalamic tracts (STs), posterior funiculus, and bilateral lateral corticospinal tracts (LCTs), respectively, at the levels of cervical 2-4 vertebral bodies. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of these ROIs were estimated. Independent sample t test and Pearson correlation analysis were used.In patients with ALS, no abnormal findings were noted in the cervical spinal cord on conventional MRI. FA values of bilateral LCTs decreased significantly compared to those of the control group (P < .05), and ADC values of bilateral LCTs were significantly greater than those of the control group (P < .05). FA and ADC values of bilateral LCTs showed no significant difference between patients with definite and probable ALS (P > .05). No significant correlation existed between abnormal DTI parameters (FA and ADC values of bilateral LCTs) and clinical parameters (P > .05).Subtle abnormalities in bilateral LCTs in the "normal-appearing" cervical spinal cord can be detected using quantitative DTI technique in patients with ALS.

Changes in cerebral blood flow (CBF) may occur with acute exposure to high altitude; however, the CBF of the brain parenchyma has not been studied to date. In this study, identical magnetic resonance scans using arterial spin labeling (ASL) were performed to study the haemodynamic changes at both sea level and high altitude. We found that with acute exposure to high altitude, the CBF in acute mountain sickness (AMS) subjects was higher (P < 0.05), while the CBF of non-AMS subjects was lower (P > 0.05) compared with those at sea level. Moreover, magnetic resonance angiography in both AMS and non-AMS subjects showed a significant increase in the cross-sectional areas of the internal carotid, basilar, and middle cerebral arteries on the first day at high altitude. These findings support that AMS may be related to increased CBF rather than vasodilation; these results contradict most previous studies that reported no relationship between CBF changes and the occurrence of AMS. This discrepancy may be attributed to the use of ASL for CBF measurement at both sea level and high altitude in this study, which has substantial advantages over transcranial Doppler for the assessment of CBF.

Individuals with intracranial artery occlusion have high rates of ischaemic events and recurrence. It has been challenging to identify patients who had high-risk stroke using a simple, valid and non-invasive screening approach. This study aimed to investigate whether fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH), a specific imaging sign on the FLAIR sequence, could be a predictor of ischaemic events in a population with internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion.We retrospectively analysed 147 patients (mean 60.43±12.83 years) with 149 lesions, including 37 asymptomatic and 112 symptomatic cases of ICA or MCA occlusion. Symptomatic occlusion was considered if ischaemic events were present in the relevant territory within 90 days. FVH Alberta Stroke Program Early Computed Tomography Score (FVH-ASPECTS: 0-7, with 0 indicating absence of FVH and 7 suggesting prominent FVH) and collateral circulation grade were assessed for each participant. Multivariable logistic regression analysis was performed to detect independent markers associated with symptomatic status.A lower FVH-ASPECTS was associated with a more favourable collateral circulation grade (rho=-0.464, p<0.0001). The FVH-ASPECTS was significantly lower in the asymptomatic occlusion group than in the symptomatic occlusion group (p<0.0001). FVH-ASPECTS (Odd ratio, 2.973; 95% confidence interval, 1.849 to 4.781; p<0.0001) was independently associated with symptomatic status after adjustment for age, sex, lesion location and collateral circulation grade in the multivariate logistic regression. The area under the curve was 0.861 for the use of FVH-ASPECTS to identify symptomatic occlusion.The ability to discriminate symptomatic from asymptomatic occlusion suggests that FVH may be a predictor of stroke. As a simple imaging sign, FVH may serve as a surrogate for haemodynamic impairments and can be used to identify high-risk stroke cases early in ICA or MCA occlusion.

Cerebral blood flow (CBF) in the human primary visual cortex is correlated with the loss of visual function in neuro-ophthalmological diseases. Advanced three-dimensional pseudo-continuous arterial spin labeling (3D pCASL), as a non-invasive method to access the CBF, can be a novel measurement to detect the visual cortex. The objective of the study was to assess the intra- and inter-scanner reliability of 3D pCASL of the visual cortex in healthy adults and suggest the selection of different post-labeling delay times (PLDs). For this reason, 3D pCASL was conducted in two 3.0T MR three times with twelve healthy volunteers at an interval of 10-15 days. The 1st and 3rd tests were performed on scanner-1, and the 2nd test was performed on scanner-2. The value of the CBF was abstracted from the visual cortex with two PLDs. The intra- and inter-scanner reliability and reproducibility were evaluated with the intraclass correlation coefficient (ICC) and Bland-Altman plots. By estimating the mean value of the CBF in the visual cortex, the intra-scanner results demonstrated the higher reliability (ICC for PLD = 1.5 second presented at 0.743 compared with 0.829 for PLD = 2.5 seconds), and the Bland-Altman plots showed the reproducibility at a longer PLD. We conclude that the calibrated 3D pCASL approach provides a highly reproducible measurement of the CBF of the visual cortex that can serve as a useful quantitative probe for research conducted at multiple centers and for the long-term observation of the clinical effects of neuro-opthalmological diseases.

Rosai-Dorfman disease (RDD) in sellar/suprasellar region is a rare intracranial disorder. The diagnostic evaluation of this condition using magnetic resonance imaging (MRI) has seldom been described previously. The purpose of our study was to describe MRI characteristics of sellar/suprasellar region RDD.Five patients with proved sellar/suprasellar region RDD from May 2005 to March 2010 were retrospectively reviewed. All the patients had undergone magnetic resonance scanning. The number, location, signal intensity (SI), and enhancement pattern of the lesions on MRI were retrospectively evaluated.Pathological diagnosis of RDD was achieved in all 5 cases including 4 by surgery and 1 by biopsy. The most common presenting symptoms were headache (n = 4) and blurred vision (n = 3). On MRI, isolated suprasellar lesion was found in 2 cases. Suprasellar lesion combined with intrasellar, dural, intra-axial and orbital lesions was found in 3 cases. All lesions showed homogeneous isointense SI on T1-weighted images and hypointense to isointense SI on T2-weighted images except one lesion in the midbrain with slight hyperintense SI on T2-weighted images. All lesions showed homogeneous enhancement.Homogenously enhancing sellar/suprasellar masses of hypointense to isointense SI on T2-weighted images are suggestive of RDD, and central hypointensity on T2-weighted images may be a specific finding. Intra-axial and extra-axial involvements may coexist with sellar/suprasellar region RDD. Although radiological findings can provide some evidence for this rare entity, differential diagnosis is still needed.

Background Neuromyelitis optica‐optic neuritis (NMO‐ON) patients are routinely treated with intravenous methylprednisolone (IVMP). For the patients nonresponsive to IVMP, more effective but aggressive therapy of plasma exchange (PE) should be employed instead of IVMP in the first line. Purpose To assess the visual outcomes of NMO‐ON patients after IVMP by radiomics analysis of whole brain diffusion tensor imaging (DTI) data. Study Type Retrospective. Population In all, 57 NMO‐ON patients receiving IVMP therapy for 3 days. Field Strength/Sequence 3.0T; DTI images acquired by a single‐shot echo planar image sequence; T 1 images acquired by 3D fast spoiled gradient echo (3D‐FSPGR) MRI. Assessment In all, 200 DTI measures were extracted from the DTI data and employed as features to construct a radiomics assessment model for visual outcomes of NMO‐ON patients after IVMP. The assessment performance was evaluated by area under the receiver operating characteristic curve (AUC), classification accuracy (ACC), sensitivity, specificity, and positive and negative predicted values (PPV and NPV). The selected DTI measures would reveal the white matter impairments related to visual recovery of NMO‐ON patients. Statistical Tests The relationship between the selected DTI measures and the clinical visual characteristics were investigated by Pearson correlation, Spearman's rank correlation, and one‐way analysis of variance analysis. Results The radiomics model obtained an ACC of 73.68% ( P = 0.002), AUC of 0.7931, sensitivity of 0.6207, specificity of 0.8571, PPV of 0.8182, and NPV of 0.6857 in assessing visual outcomes of the NMO‐ON patients after IVMP treatment. The selected DTI measures revealed white matter impairments related to the visual outcomes in the white matter tracts of vision‐relevant regions, motor‐related regions, and corpus callosum. The white matter impairments were found significantly correlated with the disease duration and the length of lesions in the optic nerve. Data Conclusion Radiomics analysis of DTI data has great potential in assessing visual outcomes of NMO‐ON patients after IVMP therapy. Level of Evidence: 2 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;49:1365–1373.

The ability of the ivy sign on contrast-enhanced T1-weighted MR imaging (CEMR) to reflect cerebral perfusion and postoperative revascularization in Moyamoya disease remains largely unknown. We aimed to compare the capabilities of CEMR and FLAIR.CEMR, FLAIR, arterial spin-labeling, and DSA were performed in 44 patients with Moyamoya disease. The ivy sign was scored separately on CEMR and FLAIR using the Alberta Stroke Program Early CT Score. The status of leptomeningeal collaterals was scored on DSA. The postoperative Matsushima grade was evaluated at least 3 months after surgical revascularization.Scoring of the ivy sign on CEMR showed excellent interrater reliability, and FLAIR vascular hyperintensity showed moderate interrater reliability. Correlation analyses revealed that DSA scores were more consistent with the CEMR-based ivy sign score (r = 0.25, P = .03) than with FLAIR vascular hyperintensity (r = 0.05, P = .65). The CEMR-based ivy sign score was significantly correlated with CBF in late-Suzuki stage Moyamoya disease (t = -2.64, P = .02). The CEMR-based ivy sign score at baseline was significantly correlated with the postoperative Matsushima grade (r = 0.48, P = .03).In this study, CEMR outperformed FLAIR in capturing the ivy sign in Moyamoya disease. In addition, the CEMR-based ivy sign score provided adequate information on hemodynamic status and postoperative neovascularization. The current study suggested that CEMR could be considered as an alternative to FLAIR in future studies investigating leptomeningeal collaterals in Moyamoya disease.

OBJECTIVE On the basis of the characteristics of occluded segments on high-resolution magnetic resonance vessel wall imaging (MR-VWI), the authors evaluated the role of high-resolution MR-VWI–guided endovascular recanalization for patients with symptomatic nonacute intracranial artery occlusion (ICAO). METHODS Consecutive patients with symptomatic nonacute ICAO that was refractory to aggressive medical treatment were prospectively enrolled and underwent endovascular recanalization. High-resolution MR-VWI was performed before the recanalization intervention. The characteristics of the occluded segments on MR-VWI, including signal intensity, occlusion morphology, occlusion angle, and occlusion length, were evaluated. Technical success was defined as arterial recanalization with modified Thrombolysis in Cerebral Infarction grade 2b or 3 and residual stenosis &lt; 50%. Perioperative complications were recorded. The characteristics of the occluded segments on MR-VWI were compared between the recanalized group and the failure group. RESULTS Twenty-five patients with symptomatic nonacute ICAO that was refractory to aggressive medical treatment were consecutively enrolled from April 2020 to February 2021. Technical success was achieved in 19 patients (76.0%). One patient (4.0%) had a nondisabling ischemic stroke during the perioperative period. Multivariable logistic analysis showed that successful recanalization of nonacute ICAO was associated with occlusion with residual lumen (OR 0.057, 95% CI 0.004–0.735, p = 0.028) and shorter occlusion length (OR 0.853, 95% CI 0.737–0.989, p = 0.035). CONCLUSIONS The high-resolution MR-VWI modality could be used to guide endovascular recanalization for nonacute ICAO. Occlusion with residual lumen and shorter occlusion length on high-resolution MR-VWI were identified as predictors of technical success of endovascular recanalization for nonacute ICAO.

Objective To evaluate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) and three-dimensional arterial spin labelling perfusion imaging (3D-ASL) in distinguishing cavernous haemangioma from parasellar meningioma, using histological data as a reference standard. Methods Patients with parasellar meningioma or parasellar cavernous haemangioma underwent conventional T 1 - and T 2 -weighted magnetic resonance imaging (MRI) followed by DWI and 3D-ASL using a 3.0 Tesla MRI. The minimum apparent diffusion coefficient (minADC) from DWI and the maximal normalized cerebral blood flow (nCBF) from 3D-ASL were measured in each tumour. Diagnosis was confirmed by histology. Results MinADC was significantly lower and nCBF significantly higher in meningioma ( n = 19) than cavernous haemangioma ( n = 15). There was a significant negative correlation between minADC and nCBF ( r = −0.605). Conclusion DWI and 3D-ASL are useful in differentiating cavernous haemangiomas from parasellar meningiomas, particularly in situations when the appearance on conventional MRI sequences is otherwise ambiguous.

Background The marginal division (MrD) is an important subcortical center involved in learning and memory. Mild cognitive impairment (MCI) is commonly seen in patients with Parkinson's disease (PD), but the neurobiological basis is yet to be elucidated. Purpose To use resting‐state functional magnetic resonance imaging (rs‐fMRI) to explore the altered functional connectivity (FC) of the MrD in patients with PD‐MCI. Study Type Prospective pilot study. Population Twenty‐five patients with PD‐MCI; 25 PD patients and no cognitive impairment (PD‐NCI); and 25 healthy control (HC) participants. Sequence 3.0 T GE Healthcare MRI scanner; three‐dimensional T 1 ‐weighted fast spoiled gradient recalled echo (3D T 1 ‐FSPGR); rs‐fMRI. Assessment The MrD was defined using manual delineation, which was the seed point to compute the FC to examine correlations between low‐frequency fMRI signal fluctuations in MrD and the whole brain. Statistical Tests Between‐group comparisons of the rs‐fMRI data were computed using two‐sample t ‐tests in a voxelwise manner after controlling for age and sex, to determine the brain regions that showed significant differences in FC with the bilateral MrDs. Correlation analyses were performed for FC values and cognitive abilities in patients with PD. Results In the PD‐MCI group, compared with the PD‐NCI group, we observed lesser FC between the MrD bilaterally and right putamen, left insula, left cerebellum, and left thalamus; greater FC between the MrD bilaterally and left middle cingulate cortex, left middle frontal gyrus, left superior frontal gyrus, left supplementary motor area, and left middle/inferior occipital gyrus. Moreover, the strength of FC between the MrD and regions that showed differences between the PD‐MCI and PD‐NCI groups was significantly correlated with neuropsychological scores in patients with PD. Data Conclusion The current study suggests that MrD dysfunction may contribute to MCI in PD. However, the mechanisms underlying this process require further investigation. Level of Evidence 1. Technical Efficacy Stage 2. J. Magn. Reson. Imaging 2019;50:183–192.

A smart multitool platform for theranostics would be useful for monitoring the administration of therapies in vivo. However, the integration of multiple functions into a single small-molecule platform remains a challenge. In this study, we developed a multifunctional probe based on a small-molecule platform. The properties of this probe were investigated via hyperpolarized 129Xe NMR/MRI, fluorescence imaging in cells and in vivo, and photodynamic therapy (PDT) in tumor mouse models. This multifunctional probe shows good pH response across a broad range of pH values. It also exhibits excellent fluorescence in vivo for mapping its biodistribution. Additionally, it produces enough 1O2 radicals for in vivo PDT. The combination of these functionalities into a single small-molecule platform, rather than a bulky nanoconstruct, offers unique possibilities for molecular imaging and therapy.

Background and Purpose: The Enterprise stent has been used for treating intracranial atherosclerotic stenosis (ICAS), but its long-term outcome remains unclear. The purpose of this study was to evaluate the long-term clinical efficacy of the Enterprise stent used for patients with symptomatic ICAS due to hypoperfusion. Method: Patients with symptomatic ICAS due to hypoperfusion treated with the Enterprise stents from a high-volume stroke center were evaluated. The successful recanalization was defined as the Modified Thrombolysis In Cerebral Infarction (mTICI) ≥ 2b. The stroke and neurological death that occurred within 72 h after the procedure as well as long-term clinical and imaging outcomes were analyzed. Results: Overall, 130 patients with 130 ICAS treated with the Enterprise stent were included in our study. The successful recanalization rate was 100%. The mean pre- and postprocedural stenosis was 82.9 ± 8.9% vs. 15.1 ± 8.4%. Periprocedural complications occurred in 5 (3.8%) patients within 72 h after the procedure. Clinical follow-up data were available in 125 (96.2%) patients (median, 24 months) and any stroke or neurological death was encountered in 6 (4.8%) patients. Angiographic follow-up data was obtained from 118 (90.8%) patients (median, 13.5 months). In addition, 1-year in-stent restenosis (&amp;gt;70%) was found in 17 (14.4%) patients, and among them, 4 (23.5%) patients were symptomatic. Conclusion: Deployment of Enterprise stent is safe for ICAS. The short-term and long-term outcomes were acceptable, but the efficacy of the Enterprise stent needs to be further evaluated in future studies.

ADVERTISEMENT RETURN TO ISSUEPREVAdditions and Correc...Additions and CorrectionsNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to Targeted Brain Delivery of Rabies Virus Glycoprotein 29-Modified Deferoxamine-Loaded Nanoparticles Reverses Functional Deficits in Parkinsonian MiceLinhao YouLinhao YouMore by Linhao You, Jing WangJing WangMore by Jing Wang, Tianqing LiuTianqing LiuMore by Tianqing Liuhttps://orcid.org/0000-0002-9058-2643, Yinlong ZhangYinlong ZhangMore by Yinlong Zhang, Xuexiang HanXuexiang HanMore by Xuexiang Hanhttps://orcid.org/0000-0003-0011-5222, Ting WangTing WangMore by Ting Wang, Shanshan GuoShanshan GuoMore by Shanshan Guo, Tianyu DongTianyu DongMore by Tianyu Dong, Junchao XuJunchao XuMore by Junchao Xu, Gregory J. AndersonGregory J. AndersonMore by Gregory J. Anderson, Qiang LiuQiang LiuMore by Qiang Liu, Yan-Zhong Chang*Yan-Zhong ChangMore by Yan-Zhong Chang, Xin Lou*Xin LouMore by Xin Lou, and Guangjun Nie*Guangjun NieMore by Guangjun Niehttps://orcid.org/0000-0001-5040-9793Cite this: ACS Nano 2022, 16, 11, 19605Publication Date (Web):October 20, 2022Publication History Received13 October 2022Published online20 October 2022Published inissue 22 November 2022https://doi.org/10.1021/acsnano.2c10134Copyright © 2022 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views657Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertsSUBJECTS:Anatomy,Nanoparticles,Peptides and proteins,Rodent models,Toxicity Get e-Alerts

This study aimed to evaluate the diagnostic value of ultrahigh-field magnetic resonance imaging (MRI) for brain tumors in clinical practice.Thirty patients with brain tumors underwent 7- and 3-T MRI. The performance and diagnostic confidence of 7- and 3-T MRI in the visualization of tumor details such as internal structure and feeding artery were evaluated by radiologists. Contrast-enhanced region performance and tumor detail diagnostic confidence score (DCS) were calculated and compared between 7 and 3T using Wilcoxon rank sum test.In 19 with obvious enhancement and 11 cases without obvious enhancement, 7- and 3-T MRI showed similar performance. The tumors' internal structure and feeding artery were more clearly depicted by 7-T MRI (62.2% and 54.4%, respectively) than by 3-T MRI (2.2% and 6.7%, respectively). Furthermore, the mean DCSs of both internal structure and feeding artery were higher at 7T than at 3T (internal structure: 16.29 ± 9.67 vs. -5.79 ± 4.12, p = 0.028; feeding artery: 21.96 ± 6.93 vs. 4.46 ± 7.07, p = 0.028). The DCS was more significantly improved in the senior radiologist group.Better visualization of brain tumor details and higher tumor detail diagnostic confidence can be obtained with 7-T MRI.

Cerebral small vessel disease (CSVD) commonly coexists with intracranial atherosclerotic stenosis (ICAS). In-stent restenosis (ISR) affects the nonprocedural outcome of severe symptomatic ICAS after intracranial stenting. However, only 8%-27% of ISR patients are symptomatic, which highlights the importance of the investigation of risk factors associated with symptomatic ISR (SISR) to improve long-term functional outcome. Whether CSVD is associated with SISR remains unclear. The authors tested the hypothesis that CSVD is associated with SISR in ICAS patients after intracranial stenting.This retrospective study enrolled 97 patients who were symptomatic due to severe anterior circulation ICAS treated with intracranial stenting. SISR was evaluated with clinical and vascular imaging follow-up. CSVD subtypes, including white matter hyperintensities (WMHs), enlarged perivascular spaces, and chronic lacunar infarctions, were evaluated. Cox regression analysis was used to compare the incidence of SISR between patients with and without CSVD.Of the enrolled patients, 58.8% had CSVD. The 1- and 2-year ISR rates were 24.7% and 37.1%, respectively. Of the CSVD subtypes, SISR was associated with deep WMHs (DWMHs; HR 5.39, 95% CI 1.02-28.44). DWMH Fazekas scale grades 2 (HR 85.54, 95% CI 2.42-3018.93) and 3 (HR 66.24, 95% CI 1.87-2352.32) were associated with SISR, but DWMH Fazekas grades 0 and 1 were not. The proportions of SISR in patients with DWMH Fazekas grades 0, 1, 2, and 3 were 16.7%, 33.3%, 50%, and 100%, respectively.Patients with CSVD have a higher risk of SISR than those without CSVD. Of the CSVD subtypes, patients with DWMHs are associated with SISR. The DWMH Fazekas scale score is considered to be a predictor for SISR.

Structured video text information extraction is a crucial part of video understanding for exploring the structured text fields from different category-specific videos such as scores in basketball games or identities in news. Recent natural language models and text detectors have demonstrated state-of-the-art performance in video text detection and recognition. However, understanding text from unstructured video frames is challenging in practice due to a variety of video text and dynamic text layout changes. Limited work has focused on the solutions that efficiently extract structured information from the video text. In this paper, we address this task by modeling a multi-modal attention graph on the video text. Specifically, we encode both the visual and textual features of detected text regions as nodes of the graph; the spatial layout relationship of the text regions is modeled as edges of the graph. The structured information extraction is solved by iteratively propagating text region messages along graph edges and reasoning the structured categories of graph nodes. To promote the representation capacity of the graph, we further introduce a contrastive loss on the visual embeddings of the text regions in a self-supervised manner. In order to roundly evaluate our proposed method as well as boost future research, we release a new dataset collected and annotated from several standard NBA regular seasons and playoff match videos. Experimental results demonstrate the superior performance of the proposed method over several state-of-the-art methods.

Background: Regional differences in gray matter volume (GMV) have been reported to be a reliable marker for diagnosing Parkinson’s disease (PD). This study aimed to explore the clinical value of GMV to assess magnetic resonance imaging-guided focused ultrasound (MRgFUS) thalamotomy as a treatment for tremor-dominant PD (TDPD). Methods: Nine TDPD patients with MRgFUS thalamotomy were recruited for structural magnetic resonance image (MRI) scanning and clinical score evaluation. GMV was calculated. To investigate changes after treatment, voxel- and region of interest (ROI)-wise GMV analyses were performed. Then, GMV with significant differences was extracted from patients to investigate its dynamic alterations by one-way repeated-measures analysis of variance (ANOVA). The nonparametric Spearman rank correlation analysis was used to evaluate the relationship between GMV alterations and tremor improvement after thalamotomy. Results: Tremors were significantly relieved after MRgFUS thalamotomy in nine patients (P<0.05). The treated hand tremor scores improved 74.82% on average in patients from pre-operation to 12 months post-operation. Voxel-wise analysis at the cluster level showed a significant decrease in GMV in the left middle occipital gyrus (MOG) [t=11.81, voxel-level P<0.001, cluster-level Pfamily-wise error (FWE) <0.05] and an increase in GMV in the left precentral gyrus (PreCG) (t=7.99, voxel-level P<0.001, cluster-level PFWE <0.05) in TDPD patients from preoperative to 12 months post-operation, which was significantly correlated with tremor scores (rho =0.346–0.439, P<0.05). ROI-wise analysis showed that GMV related to MRgFUS thalamotomy was associated with long-term structural alterations (P<0.05 with Bonferroni correction), including specific basal ganglia and related nuclei and cerebellum subregions. Conclusions: GMV can be used to reflect tremor improvement after MRgFUS thalamotomy and be helpful to better understand the distant effect of MRgFUS thalamotomy and the involvement of GMV in tremor control in TDPD. Trial Registration: ClinicalTrials.gov identifier: NCT04570046.

Ultra-high field 7T MRI can provide excellent tissue contrast and anatomical details, but is often cost prohibitive, and is not widely accessible in clinical practice.To generate synthetic 7T images from widely acquired 3T images with deep learning and to evaluate the feasibility of this approach for brain imaging.Prospective.33 healthy volunteers and 89 patients with brain diseases, divided into training, and evaluation datasets in the ratio 4:1.T1-weighted nonenhanced or contrast-enhanced magnetization-prepared rapid acquisition gradient-echo sequence at both 3T and 7T.A generative adversarial network (SynGAN) was developed to produce synthetic 7T images from 3T images as input. SynGAN training and evaluation were performed separately for nonenhanced and contrast-enhanced paired acquisitions. Qualitative image quality of acquired 3T and 7T images and of synthesized 7T images was evaluated by three radiologists in terms of overall image quality, artifacts, sharpness, contrast, and visualization of vessel using 5-point Likert scales.Wilcoxon signed rank tests to compare synthetic 7T images with acquired 7T and 3T images and intraclass correlation coefficients to evaluate interobserver variability. P < 0.05 was considered significant.Of the 122 paired 3T and 7T MRI scans, 66 were acquired without contrast agent and 56 with contrast agent. The average time to generate synthetic images was ~11.4 msec per slice (2.95 sec per participant). The synthetic 7T images achieved significantly improved tissue contrast and sharpness in comparison to 3T images in both nonenhanced and contrast-enhanced subgroups. Meanwhile, there was no significant difference between acquired 7T and synthetic 7T images in terms of all the evaluation criteria for both nonenhanced and contrast-enhanced subgroups (P ≥ 0.180).The deep learning model has potential to generate synthetic 7T images with similar image quality to acquired 7T images.2 TECHNICAL EFFICACY: Stage 1.

Deep learning has yielded promising results for medical image diagnosis but relies heavily on manual image annotations, which are expensive to acquire. We present Cross-DL, a cross-modality learning framework for intracranial abnormality detection and localization in head computed tomography (CT) scans by learning from free-text imaging reports. Cross-DL has a discretizer that automatically extracts discrete labels of abnormality types and locations from reports, which are utilized to train an image analyzer by a dynamic multi-instance learning approach. Benefiting from the low annotation cost and a consequent large-scale training set of 28,472 CT scans, Cross-DL achieves accurate performance, with an average area under the receiver operating characteristic curve (AUROC) of 0.956 (95% confidence interval: 0.952-0.959) in detecting 4 abnormality types in 17 regions while accurately localizing abnormalities at the voxel level. An intracranial hemorrhage classification experiment on the external dataset CQ500 achieves an AUROC of 0.928 (0.905-0.951). The model can also help review prioritization.

Tumefactive demyelinating disease is a rare inflammatory demyelinating disease (IDD) of the central nervous system (CNS). The literature lacks a clear and consistent description of the clinical and radiological spectrum of this disorder, and few Chinese cases have been studied. Here we report 17 Chinese patients, with pathology confirmed CNS IDD, who had distinct clinical and imaging features from those in previous reports. Median age at onset was 47 years, with a female to male ratio of 1.1:1. Multifocal lesions were present in nine cases (53%) on their pre-biopsy magnetic resonance imagings (MRIs), with locations predominantly involving periventricular white matter (41%), subcortical white matter (41%), juxtacortical regions (41%), and cortical gray matter (35%). Moderate to severe perilesional edema and/or mass effect were present in 35% of cases. A variety of enhancement patterns were observed; most were heterogenous, including ring-like, patchy, venular-like, nodular, punctate, and diffuse in a decreased frequency. Perilesional restriction on diffusion-weighted images (DWI) were evident in 70% cases. Clinical course prior to biopsy was a first neurological event in 82% cases. During a median follow-up of 4.1 years, 76% of cases remained as isolated demyelinating syndrome, and 70% experienced a total or near-total recovery regardless of whether they received immunotherapy. Further studies are needed, especially concerning series with pathological confirmation and long-term follow-up information.

Early diagnosis and treatment of herpes simplex encephalitis are crucial to reduce morbidity and mortality. Our aim was to investigate the role of 3D pseudocontinuous arterial spin-labeling in herpes simplex encephalitis.From 2014 to 2019, seventeen consecutive patients with herpes simplex encephalitis and 15 healthy volunteers were recruited in the study. Conventional MR imaging and 3D pseudocontinuous arterial spin-labeling were performed in all subjects. According to the disease duration, the lesions were classified into 3 groups, including acute, subacute, and chronic stages, respectively. Clinical, neuroradiologic, and follow-up features were studied. The normalized lesion/normal tissue CBF values of lesions at different stages were measured and compared with those in the control group, respectively.Compared with the control group, herpes simplex encephalitis demonstrated hyperperfusion in 11 acute cases and 6 subacute cases and hypoperfusion in 6 chronic cases. The mean normalized lesion/normal tissue CBF values of the lesions were 2.68 ± 0.54 in the acute stage, 2.42 ± 0.52 in the subacute stage, and 0.87 ± 0.30 in the chronic stage, respectively. The mean normalized lesion/normal tissue CBF values of acute and subacute lesions were significantly higher than those of the control group (1.33 ± 0.08; P < .001, respectively), while the mean normalized lesion/normal tissue CBF values of chronic lesions were lower than those of the control group (P < .05). Gradual perfusion reduction on serial 3D pseudocontinuous arterial spin-labeling was observed in herpes simplex encephalitis after effective therapy.Conventional MR imaging remains most helpful in the diagnosis of herpes simplex encephalitis, while 3D pseudocontinuous arterial spin-labeling could be an adjunctive technique by providing dynamic CBF features at different stages in herpes simplex encephalitis.

Background Diffusion tensor imaging (DTI) has been used for the evaluation of the white matter integrity. In this study, we evaluated optic nerve impairment in patients with neuromyelitis optica (NMO) using DTI. Methodology/Principal Findings Optic nerve DTI were performed on 28 NMO patients and 38 normal controls. Fractional anisotropy (FA) values were measured in the anterior, middle, and posterior parts of the intraorbital optic nerve segment. For the posterior intraorbital optic nerve, FA values of BI (0.20±0.07), MI (0.24±0.16), and NA (0.25±0.14) decreased significantly compared with that of NC (0.43±0.07) (P<0.05), and ROC analysis demonstrated that the area under the curve (AUC) measurements for BI vs. NC, MI vs. NC, NA vs. NC, and NMO (including BI, MI, and NA) vs. NC were 0.99, 0.93, 0.88, and 0.96, respectively. The corresponding diagnostic sensitivities of ROC analysis were 100%, 80%, 80%, and 91%; and the specificities were 93%, 97%, 91%, and 93%. Conclusions/Significance Decreased FA value in the intraorbital optic nerve, especially in the posterior part of the nerve, was demonstrated as a characteristic MR feature for NMO-related optic nerve impairment.

Small vessel disease (SVD) shares common vascular risk factors with large artery disease (LAD). However, little is known about the relationship between intracranial artery stenosis and SVD burden.To investigate whether SVD burden correlates with severity of intracranial LAD.Retrospective.Five hundred and sixteen patients with LAD of arterial circulation were enrolled from one hospital, including 384 males (59 ± 11 years) and 132 females (60 ± 12 years).3 T. T1 -weighted fast spin echo (T1 W FSE), T2 W FSE, T2 fluid attenuated inversion recovery, diffusion-weighted imaging, susceptibility-weight imaging, and time-of-flight magnetic resonance angiography.The LAD was divided into mild stenosis (<30%), moderate stenosis (30%-69%), and severe stenosis (≥70%). The Standard for Reporting Vascular Changes on Neuroimaging criteria was used to rate the SVD burden according to the level of white matter hyperintensity (WMH), perivascular space (PVS), cerebral microbleed (CMB), and lacunes.Lilliefors test, ANOVA, chi-squared test, Mann-Whitney U test, Wilcoxon signed rank test, Bonferroni test, Spearman's correlation, logistic regression, and Cohen's kappa test.The grade scores for centrum semiovale PVS (CS-PVS) were positively correlated with the degree of stenosis (R = 0.413), whereas the presence of severe basal ganglia PVS (BG-PVS) was associated with CMB (R = 0.508), lacunes (R = 0.365), and severe WMH (R = 0.478). In multivariate analysis, severe CS-PVS (adjusted odds ratio [aOR], 3.1; 95% confidence interval [CI], 1.9-4.8) and lacunes (aOR, 2.1; 95% CI, 1.3-3.4) were associated with severe stenosis of LAD. In addition, CS-PVS was related to severe stenosis in a dose-dependent manner: when CS-PVS score was 3 and 4, the aORs of severe stenosis were 1.9 and 7.7, respectively.The severity of LAD in anterior circulation is associated with SVD burden, which suggests that different SVD burden may be used for risk stratification in LAD.3 TECHNICAL EFFICACY: Stage 3.

To determine the efficacy of susceptibility-weighted imaging (SWI) in the differential diagnosis between basal ganglia (BG) infarct-like early stage intracranial ectopic germinomas (IEGs) and subacute lacunar infarct (SLI).Six children with early stage BG IEGs displaying an infarct-like episode proven by pathology and eight children with BG SLI proven by clinic and vascular imaging were investigated retrospectively. On SWI, the contrast-to-noise ratio (CNR) in abnormal signal intensity regions was calculated and compared between the two groups.For both IEGs and SLI the BG lesions were invisible or showed slight hyperintensity/hypointensity on T1-weighted images and diffusion-weighted images, patchy slight hyperintensity on T2-weighted images without mass effect, and variable enhancement on postcontrast magnetic resonance imaging (MRI). On SWI, obvious hypointensity in BG lesions and pineal gland (PG) was found in IEG patients but unremarkable in SLI patients. The CNRs of BG lesions and PG were significantly higher in IEG patients compared with those in SLI patients (P < 0.01).SWI is useful in differentiating IEGs from SLI when clinical symptoms and conventional MRI manifestations overlap in these two conditions. PG may be involved with tumor, although it is normal on conventional MRI in patients with IEGs.

Background Based on recent clinical data, an imaging strategy of identifying proximal coronary disease allows further management decisions in patients with stable angina pectoris. We aimed to compare diagnostic accuracy of non-contrast fast steady-state (FIESTA) magnetic resonance angiography (MRA) with 64-multidetector computed tomographic angiography (CTA), using conventional coronary angiography (CA) as the reference standard. Methods Thirty patients with suspected coronary artery disease consented to participate in an institutional review board-approved protocol. Coronary MRA was performed at 1.5 T using a respiratory navigator and electrocardiogram-gated three-dimensional FIESTA pulse sequence. CTA images were acquired using a 64-multidetector computed tomographic scanner, using beta blockade to reduce the heart rate to less than 70 bpm. Coronary luminal stenosis >50% was identified. Plaques were classified as non-calcified, mixed, or calcified on CTA, and as high-, intermediate-, or low-signal on FIESTA MRA. Results Compared to CA, the sensitivity, specificity, and overall accuracy for detection of >50% proximal coronary stenoses were 83.0%, 86.9%, and 86.1% for MRA and 85.1%, 87.2%, and 86.8% for CTA, respectively. For the 24 calcified stenoses, MRA corrected 16 segments that overestimated on CTA and MRA had an accuracy of 75% in evaluating calcified plaques. Conclusions High-resolution three-dimensional FIESTA MRA and CTA have a similar accuracy in detecting proximal coronary stenosis. The clinical impact of identification of proximal disease in patients with stable CAD needs to be examined in future studies.

Abstract Background The relationship between intracranial vessel configuration and wall features remains poorly investigated. Therefore, we aimed to investigate the relationship between the distal and proximal anatomical configuration of basilar artery (BA) and BA vessel wall features on high-resolution magnetic resonance imaging (HRMRI). Methods From September 2014 to January 2017, patients with suspected symptomatic intracranial arterial stenosis underwent HRMRI. Patients with severe BA stenosis were selected for this prospective study and divided into two groups corresponding to complete and incomplete BA configuration based on characteristics of the bilateral vertebral arteries and posterior cerebral arteries. Culprit blood vessel wall features on HRMRI included plaque enhancement, intraplaque hemorrhage, remodeling patterns, and plaque distribution. Culprit vessel wall features were compared between patients in the complete and incomplete BA configuration groups. Results Among the 298 consecutively enrolled patients, 34 had severe BA stenosis. Twenty patients had complete anatomical BA configuration and another 14 of them displayed incomplete configuration. There were no significant differences in vessel wall features between the complete and incomplete configuration patient groups. However, the proximal configuration of BA was associated with intraplaque hemorrhage ( p = 0.002) while the distal configuration of BA correlated with strong enhancement of BA plaque ( p = 0.041). Conclusions No association was found between the complete and incomplete BA configuration groups and blood vessel wall features. The proximal configuration of BA was related with intraplaque hemorrhage and the distal configuration of BA was associated with strong plaque enhancement. Further studies are warranted to confirm these findings. Trial registration URL: Unique identifier: NCT02705599 (March 10, 2016).

Auditory neuropathy (AN) is the term used to describe a group of hearing disorders, in which the hearing impairment occurs as a result of abnormal auditory nerve function. While our understanding of this condition has advanced significantly over recent years, the ability to determine the site of lesion and the extent of dysfunction in affected individuals remains a challenge. To this end, we investigated potential axonal degeneration in the white matter tracts of the brainstem in individuals with X-linked AN. We hypothesized that individuals with X-linked AN would show focal degeneration within the VIII nerve and/or auditory brainstem tracts, and the degree of degeneration would correlate with the extent of auditory perceptual impairment.This was achieved using a higher-order diffusion magnetic resonance imaging (dMRI)-based quantitative measure called apparent fiber density as obtained from a technique called single-shell 3-tissue constrained spherical deconvolution and analyzed with the fixel-based analysis framework. Eleven subjects with genetically confirmed X-linked AN and 11 controls with normal hearing were assessed using behavioral and objective auditory measures. dMRI data were also collected for each participant.Fixel-based analysis of the brainstem region showed that subjects with X-linked AN had significantly lower apparent fiber density in the VIII nerve compared with controls, consistent with axonal degeneration in this region. Subsequent analysis of the auditory brainstem tracts specifically showed that degeneration was also significant in these structures overall. The apparent fiber density findings were supported by objective measures of auditory function, such as auditory brainstem responses, electrocochleography, and otoacoustic emissions, which showed VIII nerve activity was severely disrupted in X-linked AN subjects while cochlear sensory hair cell function was relatively unaffected. Moreover, apparent fiber density results were significantly correlated with temporal processing ability (gap detection task) in affected subjects, suggesting that the degree of VIII nerve degeneration may impact the ability to resolve temporal aspects of an acoustic signal. Auditory assessments of sound detection, speech perception, and the processing of binaural cues were also significantly poorer in the X-linked AN group compared with the controls with normal hearing.The results of this study suggest that the dMRI-based measure of apparent fiber density may provide a useful adjunct to existing auditory assessments in the characterization of the site of lesion and extent of dysfunction in individuals with AN. Additionally, the ability to determine the degree of degeneration has the potential to guide rehabilitation strategies in the future.

A new fluorinated liposome gives instantaneous temperature-induced ¹⁹F MR signal enhancement and excellent stability under reversible signal transition.

Non-structural carbohydrates (NSCs) are an important energy source for the metabolism of plants. The size of the NSC pool is likely to mirror the overall carbon supply status and its dynamics strongly influences physiological processes in plants. In order to predict the response and adaptation of trees to climate change, this review summarized the current understanding of NSC pool in trees, and mainly focused on its seasonal and spatial variation for analyzing the relationships between environmental factors and NSC allocation. Moreover, the response and adaptation strategies of NSC pool in trees to climate change were also discussed. Finally, some suggestions were proposed for the potential study orientation of NSC pool in trees in future climate conditions.

Objective To acquire cerebral blood flow (CBF) in patients with severe intracranial atherosclerotic stenosis with enhanced pseudo-continuous arterial spin labeling (e-pCASL) and compare it with the findings of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC PWI) and pseudo-continuous arterial spin labeling (pCASL). Methods A total of 39 consecutive patients with severe intracranial atherosclerotic stenosis were enrolled in this study. All these patients underwent e-pCASL, pCASL, and DSC PWI. Blood supply territory of the stenosed artery was outlined as region of interest (ROI) and a mirror ROI was applied. Ratios of CBF were calculated as value of ROI/value of mirror ROI. SNK variance analysis was conducted to compare the CBF values of three persufion methods. Factorial analysis of variance and Pearson were employed to analysis the difference and the correlation of e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI relative cerebral blood flow(rCBF) ratio. Results The e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI rCBF ratio were not significantly different (P=0.476). TTP showed the CBF ratios were not significantly different between the healthy side and diseased side in patients with severe intracranial atherosclerotic stenosis. ATT showed the correlations of pCASL CBF ratio and DSC PWI rCBF ratio were not affected by ATT. Conclusions e-pCASL with multiple-post labeling delay time and pCASL have good consistency with DSC PWI in the quantitative measurement of hypoperfusion pattern. As an accurate, simple, non-invasive, and repeatable technique, e-pCASL has good correlation with DSC PWI in the quantitative measurement of hypoperfusion pattern that is not affected by ATT.

Background Creutzfeldt-Jakob disease (CJD), a rare disease, is uncharacterized by computed tomography (CT) and magnetic resonance imaging (MRI). This study was aimed to evaluate the diffusion-weighted MRI (DWI) manifestations of CJD and to discuss their diagnostic value. Methods The findings of T1-weighted MRI (T1WI), T2-weighted MRI (T2WI), DWI and post-contrast MRI in 5 patients (3 patients with biopsy-proven CJD and 2 patients with clinically-proven CJD) were retrospectively analyzed in this study. Results Four out of the 5 patients had cerebral atrophy of various degrees. One patient showed symmetric high signal intensity at the bilateral globus pallidus and the head of the caudate nucleus, with very high signal in the cerebral cortex on the DWI. This patient only had symmetric slightly high signal at the bilateral globus pallidus and putamen on T2WI. One patient had high signal intensity at the basal ganglia and cerebral cortex on DWI, but abnormal T2 signal intensity at the bilateral paraventricular white matter on MRI. Two patients presented with widely gyri-like high signal intensity at the cortex on DWI, but routine MRI showed bilateral paraventricular long T2 signal intensity in 1 patient and no abnormal findings in another. No abnormalities were shown by both routine MRI and DWI in the last patient. Conclusions DWI is more sensitive than its conventional counterpart in the depiction of CJD. DWI is more sensitive to detect cortical abnormal signal intensity in CJD not detected by T2WI.

Two cases with similar brain imaging findings were reported. Both brain MRIs were characterized by abnormal signal intensities in thalamus, surrounding third ventricle, periaqueductal areas and posteromedial thalami. Through clinical observation and a series of auxiliary examinations, one patient was diagnosed as Wernicke encephalopathy (WE) and the other as neuromyelitis optica (NMO). Although WE and NMO are totally different diseases entity, but similar lesions area aroused hypothesis that potential correlations may exist between these two diseases. Astrocytes may be the target cells connecting these two diseases. Potential benefit of thiamine supplementary therapy is suggested for NMO treatment.

To investigate the structural changes of marginal division (MrD) which is the high intensity zone between globus pallidus and putamen on phase image in the human brain.The structural changes of MrD were investigated based on MR phase imaging and diffusion tensor imaging (DTI) data at 3.0 Tesla (T) MR scanner in 72 volunteers. Phase value, including high iron components (HIC), low iron components (LIC), LIC ratio, and average iron components (AIC), were obtained using histogram analysis about the head of caudate nucleus (CA), globus pallidus (GP), putamen (PU), and MrD. The structural measurement of MrD was applied on corrected phase images (CPIs). Average apparent diffusion coefficient (ADC) values and fractional anisotropy (FA) values were calculated based on DTI data.MrD showed negative correlation for LIC with aging, with the highest HIC (left/right 2149.3 ± 19.6/2155.9 ± 17.9) and LIC (left/right 1996.6 ± 18.2/1999.6 ± 20.7), the lowest LIC ratio (left/right 21.5% ± 7.9%/19.4% ± 8.0%), and the highest AIC (left/right 2116.4 ± 21.4/2124.7 ± 21.0). The width (Head: left/right 2.01 ± 0.41 mm/1.86 ± 0.36 mm; Body: left/right 1.84 ± 0.38 mm/1.49 ± 0.29 mm; Tail: left/right 1.17 ± 0.36 mm/1.05 ± 0.23 mm) and area (left/right 49.44 ± 9.71 mm2 /42.75 ± 8.80 mm2 ) of MrD showed negative correlation with aging, presenting gradually narrower pattern based on CPIs. Average ADC value (left/right 0.69 ± 0.04 10-3 mm2 /s / 0.71 ± 0.03 10-3 mm2 /s) revealed negative correlation, while FA value (left/right 0.19 ± 0.03/0.22 ± 0.03) revealed positive correlation with aging.The findings suggested that the structure measurements based on CPIs and DTI could provide a simple and effective tool for the evaluation of MrD in vivo in the human brain and for the assessment of the changes seen with aging.1 J. MAGN. RESON. IMAGING 2017;45:1343-1351.