Cerebral Small Vessel Disease Burden in Patients with Transient Global Amnesia and its Relationship with Recurrence.

OBJECTIVE: Cerebral Small Vessel Disease (CSVD) has not been systematically studied in patients with Transient Global Amnesia (TGA). We aimed to investigate the CSVD burden in patients with TGA and its relationship with TGA recurrence. METHODS: We retrospectively examined 69 patients diagnosed with TGA in a single center between January 2015 and November 2023. The overall CSVD burden and single CSVD imaging markers, including enlarged perivascular spaces in the hippocampus (H-EPVS), were measured in each patient and compared with those in 69 age- and sex-matched healthy controls. Multivariate logistic regression was performed to determine independent predictors of recurrence. RESULTS: Of the 69 included patients, 40 (58%) were female, and the median age was 67 years (range 42-83 years). Twenty-one patients (30.4%) showed dot-like hippocampal hyperintensities on diffusion-weighted imaging (DWI). The mean follow-up was 51 months. Sixteen patients (23.2%) experienced TGA recurrence. The burden of overall CSVD, lacunes, WMH, EPVS, and extensive H-EPVS was higher in TGA patients than in controls. TGA patients who experienced recurrence had a heavier overall CSVD burden, lower frequency of hippocampal DWI hyperintensities, and longer follow-up duration than those who had with single episode. In the multivariate analysis, only follow-up duration was an independent predictor of TGA recurrence. CONCLUSION: The overall CSVD burden and extensive H-EPVS burden were higher in patients with TGA than healthy controls. Follow-up duration but not overall CSVD burden may predict TGA recurrence.

Prevalence and Prognostic Factors of Cortical Laminar Necrosis in Acute Ischemic Stroke.

BACKGROUND: Cortical laminar necrosis (CLN) is a specific type of cortical infarction, and little is known about its frequency and outcomes. We aimed to investigate the prevalence and outcomes of CLN caused by brain infarction and its prognostic factors. METHODS: This retrospective cohort study included patients with acute ischemic stroke (AIS) between 2019 and 2022 and for whom magnetic resonance images obtained at our center showed acute-stage CLN. Their medical records were collected and analyzed. An unfavorable outcome was defined as a modified Rankin Scale score of 3-6 at 90 days. Logistic regression was performed to identify independent predictors of an unfavorable outcome. RESULTS: Among 5548 consecutive patients with AIS, 151 patients (2.7%) were diagnosed with CLN, and 112 had CLN enrolled in the final analysis. At 90 days, 25 patients (22.3%) had an unfavorable outcome. Compared with the favorable group, poor outcome patients had higher rates of previous stroke (p = 0.012), higher National Institutes of Health Stroke Scale (NIHSS) scores at admission (p < 0.001), and were more likely to have early neurologic deterioration (END) (p = 0.014), diffuse ischemic lesions (p = 0.011), and lesions involving multiple lobes (p = 0.030). In multivariable analysis, the initial NIHSS score (OR, 1.258, (95% CI 1.090 - 1.453), p = 0.002) and END (OR, 5.695, [95% CI 1.410 - 23.007], p = 0.015) were independently associated with unfavorable outcome. CONCLUSION: CLN is a rare ischemic event but has a good prognosis in most cases. A higher initial NIHSS score and END may predict an unfavorable outcome.

Multimodal magnetic resonance imaging analysis in the characteristics of Wilson's disease: A case report and literature review.

Wilson's disease (WD) is an inherited disorder of copper metabolism. Multimodal magnetic resonance imaging (MRI) has been reported to provide evidence of the extent and severity of brain lesions. However, there are few studies related to the diagnosis of WD with multimodal MRI. Here, we reported a WD patient who was subjected to Sanger sequencing, conventional MRI, and multimodal MRI examinations, including susceptibility-weighted imaging (SWI) and arterial spin labeling (ASL). Sanger sequencing demonstrated two pathogenic mutations in exon 8 of the ATP7B gene. Slit-lamp examination revealed the presence of Kayser-Fleischer rings in both eyes, as well as low serum ceruloplasmin and high 24-h urinary copper excretion on admission. Although the substantia nigra, red nucleus, and lenticular nucleus on T1-weighted imaging and T2-weighted imaging were normal, SWI and ASL showed hypointensities in these regions. Besides, decreased cerebral blood flow was found in the lenticular nucleus and the head of caudate nucleus. The patient recovered well after 1 year and 9 months of follow-up, with only a Unified Wilson Disease Rating Scale score of 1 for neurological symptom. Brain multimodal MRI provided a thorough insight into the WD, which might make up for the deficiency of conventional MRI.

Thin-Slice Magnetic Resonance Imaging-Based Radiomics Signature Predicts Chromosomal 1p/19q Co-deletion Status in Grade II and III Gliomas.

Objective: Chromosomal 1p/19q co-deletion is recognized as a diagnostic, prognostic, and predictive biomarker in lower grade glioma (LGG). This study aims to construct a radiomics signature to non-invasively predict the 1p/19q co-deletion status in LGG. Methods: Ninety-six patients with pathology-confirmed LGG were retrospectively included and randomly assigned into training (n = 78) and validation (n = 18) dataset. Three-dimensional contrast-enhanced T1 (3D-CE-T1)-weighted magnetic resonance (MR) images and T2-weighted MR images were acquired, and simulated-conventional contrast-enhanced T1 (SC-CE-T1)-weighted images were generated. One hundred and seven shape, first-order, and texture radiomics features were extracted from each imaging modality and selected using the least absolute shrinkage and selection operator on the training dataset. A 3D-radiomics signature based on 3D-CE-T1 and T2-weighted features and a simulated-conventional (SC) radiomics signature based on SC-CE-T1 and T2-weighted features were established using random forest. The radiomics signatures were validated independently and evaluated using receiver operating characteristic (ROC) curves. Tumors with IDH mutations were also separately assessed. Results: Four radiomics features were selected to construct the 3D-radiomics signature and displayed accuracies of 0.897 and 0.833, areas under the ROC curves (AUCs) of 0.940 and 0.889 in the training and validation datasets, respectively. The SC-radiomics signature was constructed with 4 features, but the AUC values were lower than that of the 3D signature. In the IDH-mutated subgroup, the 3D-radiomics signature presented AUCs of 0.950-1.000. Conclusions: The MRI-based radiomics signature can differentiate 1p/19q co-deletion status in LGG with or without predetermined IDH status. 3D-CE-T1-weighted radiomics features are more favorable than SC-CE-T1-weighted features in the establishment of radiomics signatures.

White Matter Abnormalities of Auditory Neural Pathway in Sudden Sensorineural Hearing Loss Using Diffusion Spectrum Imaging: Different Findings From Tinnitus.

Sudden sensorineural hearing loss (SSNHL) is a complex and challenging emergency which requires evidence regarding its pathophysiological changes to guide the treatment. The aim of this study was to evaluate the white matter integrity of the auditory neural pathway in patients with unilateral SSNHL in acute stage by using diffusion spectrum imaging tractography. In the present study, 60 individuals with acute SSNHL (29 males, 50.7 ± 11.8 years) and 25 healthy controls (13 males, 45.2 ± 13.2 years) underwent diffusion spectrum imaging tractography and high resolution T1 structural examinations using a 3T magnetic resonance imaging system. The areas of the auditory neural pathway were defined as regions of interest (ROIs). The quantitative anisotropy (QA) and the generalized fractional anisotropy (GFA) were compared between the patients with unilateral SSNHL and controls in these ROIs. We further evaluated the correlation between the parameter values and hearing loss level. The mean pure tone audiometry of patients at the onset presentation was 63.2 ± 26.2 dB. The right-sided SSNHL was involved in 25 (41.7%) cases and the left-sided in 35 (58.3%) cases. The QA values in the contralateral medial geniculate body, the bilateral anterior corona radiata and the anterior limb of internal capsule were significantly reduced in SSNHL patients compared to controls. In addition, the decrease QA value of the contralateral medial geniculate body was related to the increase severity of disease, even after controlling potential confounding factors. The present study demonstrated that patients with SSNHL exhibited altered integrity of white matter in the auditory neural pathway. Furthermore, the decreased QA values in the contralateral medial geniculate body might predict the severity of this disease. In the present study, tinnitus has not been found to effect in brain area obviously.

Conventional magnetic resonance imaging-based radiomic signature predicts telomerase reverse transcriptase promoter mutation status in grade II and III gliomas.

PURPOSE: Telomerase reverse transcriptase (TERT) promoter mutation status is an important biomarker for the precision diagnosis and prognosis prediction of lower grade glioma (LGG). This study aimed to construct a radiomic signature to noninvasively predict the TERT promoter status in LGGs. METHODS: Eighty-three local patients with pathology-confirmed LGG were retrospectively included as a training cohort, and 33 patients from The Cancer Imaging Archive (TCIA) were used as for independent validation. Three types of regions of interest (ROIs), which covered the tumor, peri-tumoral area, and tumor plus peri-tumoral area, were delineated on three-dimensional contrast-enhanced T1 (3D-CE-T1)-weighted and T2-weighted images. One hundred seven shape, first-order, and texture radiomic features from each modality under each ROI were extracted and selected through least absolute shrinkage and selection operator. Radiomic signatures were constructed with multiple classifiers and evaluated using receiver operating characteristic (ROC) analysis. The tumors were also stratified according to IDH status. RESULTS: Three radiomic signatures, namely, tumoral radiomic signature, tumoral plus peri-tumoral radiomic signature, and fusion radiomic signature, were built, all of which exhibited good accuracy and balanced sensitivity and specificity. The tumoral signature displayed the best performance, with area under the ROC curves (AUC) of 0.948 (0.903-0.993) in the training cohort and 0.827 (0.667-0.988) in the validation cohort. In the IDH subgroups, the AUCs of the tumoral signature ranged from 0.750 to 0.940. CONCLUSION: The MRI-based radiomic signature is reliable for noninvasive evaluation of TERT promoter mutations in LGG regardless of the IDH status. The inclusion of peri-tumoral area did not significantly improve the performance.

Fusion Radiomics Features from Conventional MRI Predict MGMT Promoter Methylation Status in Lower Grade Gliomas.

PURPOSE: The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter has been proven to be a prognostic and predictive biomarker for lower grade glioma (LGG). This study aims to build a radiomics model to preoperatively predict the MGMT promoter methylation status in LGG. METHOD: 122 pathology-confirmed LGG patients were retrospectively reviewed, with 87 local patients as the training dataset, and 35 from The Cancer Imaging Archive as independent validation. A total of 1702 radiomics features were extracted from three-dimensional contrast-enhanced T1 (3D-CE-T1)-weighted and T2-weighted MRI images, including 14 shape, 18 first order, 75 texture, and 744 wavelet features respectively. The radiomics features were selected with the least absolute shrinkage and selection operator algorithm, and prediction models were constructed with multiple classifiers. Models were evaluated using receiver operating characteristic (ROC). RESULTS: Five radiomics prediction models, namely, 3D-CE-T1-weighted single radiomics model, T2-weighted single radiomics model, fusion radiomics model, linear combination radiomics model, and clinical integrated model, were built. The fusion radiomics model, which constructed from the concatenation of both series, displayed the best performance, with an accuracy of 0.849 and an area under the curve (AUC) of 0.970 (0.939-1.000) in the training dataset, and an accuracy of 0.886 and an AUC of 0.898 (0.786-1.000) in the validation dataset. Linear combination of single radiomics models and integration of clinical factors did not improve. CONCLUSIONS: Conventional MRI radiomics models are reliable for predicting the MGMT promoter methylation status in LGG patients. The fusion of radiomics features from different series may increase the prediction performance.

Pathophysiological Evaluation in a Case of Wernicke's Encephalopathy by Multimodal MRI.

To report a patient with Wernicke's encephalopathy (WE) using multimodal magnetic resonance imaging (MRI) including conventional MRI, diffusion-weighted MRI (DWI), arterial spin labeling (ASL), and proton MR spectroscopy (MRS). A 50-year-old woman of WE with a history of cholecystectomy and acute pancreatitis was given MRI scans including DWI, MRS, and ASL pre- and post-thiamine treatment. Two weeks after admission, the patient's condition rapidly improved. The typical MRI findings and lesions in the frontal cortex at baseline disappeared or resolved partially. The reduced apparent diffusion coefficient value in part of the thalamus lesion, the elevated cerebral blood flow in the frontal cortex, the lactate doublet peak in the right thalamus lesion, and in cerebral spinal fluid, all resolved after treatment. The combination of conventional MRI with DWI, proton MRS, and ASL, offers a powerful diagnostic tool and a better understanding of the pathophysiological and hemodynamic mechanisms.

ASL perfusion features and type of circle of Willis as imaging markers for cerebral hyperperfusion after carotid revascularization: a preliminary study.

OBJECTIVES: Cerebral hyperperfusion (CH) could be a disastrous outcome causing complication after carotid revascularization if not managed properly and timely. The aim of this study was to investigate the association between preoperative arterial spin labelling (ASL) perfusion features and circle of Willis (CoW) pattern with CH. METHODS: Forty-eight consecutive carotid stenosis patients who underwent carotid endarterectomy (CEA) or carotid artery stenting (CAS) were enrolled. All patients had single post-labelling delay (PLD) ASL, territory-ASL, and 3-dimensional time-of-flight MR angiography (3D TOF MRA) within 2 weeks before surgery and within 3 days after surgery. Spatial coefficient of variation (CoV) of cerebral blood flow (CBF), whole brain, and territory perfusion volume ratio were calculated from ASL and territory-ASL. Postoperative CoW was classified into two groups based on patency of the first segment of the anterior cerebral arteries (A1) and anterior communicating artery (AcomA). ASL perfusion features, type of CoW, and clinical characteristics were analyzed between CH group and non-CH group to identify CH risk factors. RESULTS: Higher CoV (p = 0.005) of CBF, lower whole brain perfusion volume ratio (p = 0.012), missing any of A1 or AcomA in CoW (p = 0.002 for postoperative MRA and p = 0.004 for preoperative MRA), and large artery stroke history (p = 0.028) were significantly associated with higher risk of CH. Two cases with cerebral hyperperfusion syndrome (CHS) were also discussed, and their perfusion and angiographic features were shown. CONCLUSIONS: Single-PLD ASL and MRA might be useful and non-invasive imaging tools to identify patients with higher risk of CH after carotid revascularization. KEY POINTS: • Cerebral hyperperfusion is a critical complication after carotid endarterectomy or carotid artery stenting. • ASL and MRA can be used to identify patients at higher risk of cerebral hyperperfusion • Pattern of circle of Willis, ASL perfusion features, and whole brain perfusion volume ratio are potential predicting markers for hyperperfusion after carotid revascularization.

Crossed cerebellar diaschisis in post-treatment glioma patients: A comparative study of arterial spin labelling and dynamic susceptibility contrast.

OBJECTIVES: To assess crossed cerebellar diaschisis (CCD) in post-treatment glioma patients, and to compare the performance of arterial spin labelling (ASL) and dynamic susceptibility contrast (DSC) in detecting CCD. METHODS AND MATERIALS: This retrospective study included 130 patients who had both DSC and ASL. Among them, 16 had underwent fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). We investigated the relationship between CCD and the location and size of supratentorial lesions, and compared PET diagnostic performance with that of ASL and DSC. We assessed the inter-methods agreement for ASL and DSC, and performed quantitative analysis by calculating the asymmetry index (AI) between bilateral cerebellum and exploring how the AI values for ASL-CBF, DSC-rCBF, and DSC-rCBV maps correlated with each other. RESULT: Supratentorial lesions affecting the corona radiata (P < 0.001), basal ganglia (P < 0.001), and insula (P = 0.046) were significantly associated with the occurrence of CCD. Lesion size was significantly larger (P = 0.005) in the CCD positive group. With PET as a reference, ASL-CBF and DSC-rCBF maps exhibited the best diagnostic performance compared with the other DSC-generated maps (diagnostic accuracy = 83.3% for both, area under curve (AUC) of ASL = 0.967, AUC of rCBF = 0.983), although differences were not statistically significant. The κ value for the inter-methods (ASL and DSC) agreement in detecting CCD was 0.893, while the degree of perfusion asymmetry was more significant in ASL- than DSC-generated maps. Bland-Altman plots showed that the AI for ASL-CBF was moderately correlated with those for DSC-rCBF and DSC-rCBV. CONCLUSIONS: CCD can present in post-treatment glioma patients and is detectable on MR-perfusion images including ASL-CBF, DSC-rCBF, and DSC-rCBV maps.

Evaluation of recurrent high-grade gliomas treated with bevacizumab: A preliminary report of 3D pseudocontinuous artery spin labeling.

PURPOSE: To investigate the role of cerebral blood flow (CBF) derived from a 3D fast spin echo (FSE) pseudocontinuous artery spin labeling (pcASL) sequence in evaluating the survival rate of recurrent high-grade gliomas (rHGGs) that were treated with bevacizumab (BEV). MATERIALS AND METHODS: Sixteen patients with rHGGs who underwent 3T 3D FSE pcASL imaging 1-2 days before (baseline or pre-BEV) and within 1 month after BEV treatment initiation (post-BEV) were included in the study. Average (aCBF) and maximum (mCBF) cerebral blood flow of the enhancing tumor, their respective normalized values to contralateral normal-appearing white matter (rCBF_wm and mCBF_wm) and cerebellum (rCBF_cb and mCBF_cb), and the related changes between baseline and post-BEV were evaluated. Receiver operating characteristic (ROC) curve analysis was utilized to define the optimal cutoff perfusion values for overall survival (OS) and progression-free survival (PFS) stratification. Kaplan-Meier analysis with log-rank test was applied to assess and compare PFS and OS rates. RESULTS: All the CBF measurements pre-BEV and post-BEV treatment were significantly different except mCBF. The CBF measurements (aCBF, rCBF_wm, rCBF_cb, mCBF_wm and mCBF_cb) pre-BEV all decreased post-BEV treatment. Cutoffs of aCBF (43.72 ml/100g/min) pre-BEV for OS, rCBF_cb (1.09) pre-BEV for PFS and OS, and ΔaCBF (-0.37) for PFS were found to be statistically significant in survival stratification (404 days vs. 140 days, P = 0.026; 251 days vs. 112 days, P = 0.044; 404 days vs. 194 days, P = 0.046; 267 days vs. 116 days, P = 0.048, respectively). CONCLUSION: Three dimensional FSE pcASL can detect the decrease of perfusion in rHGGs treated with BEV and is a potential promising technique in stratifying survival rate of rHGGs under BEV treatment. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:565-573.