Effect of patient sex on white matter alterations in unilateral medial temporal lobe epilepsy with hippocampal sclerosis assessed by diffusion tensor imaging

BACKGROUND AND PURPOSE: Studies shows ictal behavior and symptoms are affected by patient sex in temporal lobe epilepsy. The purpose of our study was to determine whether alterations in the WM as assessed by DTI display different patterns in male and female patients with unilateral HS. MATERIALS AND METHODS: Patients with unilateral HS were categorized as women with right HS ( n=12), men with right HS ( n=10), women with left HS ( n=12), and men with left HS ( n=10). DTI of the brain along 64 noncollinear directions was obtained from 44 patients and 37 sex-matched control participants. We used TBSS to analyze whole-brain WM. Regions with significant changes of FA and MD, and their mean FA, MD, total number of significant voxels, and asymmetry indices were determined for each group. RESULTS: All groups showed bilateral and extensive reductions of FA and elevated MD in the WM, more prominent ipsilateral to the affected hippocampus. The total number of voxels with decreased FA in patients compared with that of control participants was higher in women with right HS (24,727 vs 5,459) and in men with left HS (27,332 vs 14,013) than in their counterparts. Changes in MD associated with right HS were more extensive in both men and women (right vs left HS, women: 16,926 vs 5,458; men: 5,389 vs 4,764) than in those with left HS. In patients with right HS, the ipsilateral cingulum, uncinate fasciculus, internal and external capsules, and right acoustic radiation were involved extensively in women. CONCLUSIONS: Women and men showed different patterns in extent of WM alterations associated with HS

CEST MRI provides amide/amine surrogate biomarkers for treatment-naïve glioma sub-typing

PURPOSE: Accurate glioma classification affects patient management and is challenging on non- or low-enhancing gliomas. This study investigated the clinical value of different chemical exchange saturation transfer (CEST) metrics for glioma classification and assessed the diagnostic effect of the presence of abundant fluid in glioma subpopulations. METHODS: Forty-five treatment-naïve glioma patients with known isocitrate dehydrogenase (IDH) mutation and 1p/19q codeletion status received CEST MRI (B1rms = 2μT, Tsat = 3.5 s) at 3 T. Magnetization transfer ratio asymmetry and CEST metrics (amides: offset range 3-4 ppm, amines: 1.5-2.5 ppm, amide/amine ratio) were calculated with two models: 'asymmetry-based' (AB) and 'fluid-suppressed' (FS). The presence of T2/FLAIR mismatch was noted. RESULTS: IDH-wild type had higher amide/amine ratio than IDH-mutant_1p/19qcodel (p < 0.022). Amide/amine ratio and amine levels differentiated IDH-wild type from IDH-mutant (p < 0.0045) and from IDH-mutant_1p/19qret (p < 0.021). IDH-mutant_1p/19qret had higher amides and amines than IDH-mutant_1p/19qcodel (p < 0.035). IDH-mutant_1p/19qret with AB/FS mismatch had higher amines than IDH-mutant_1p/19qret without AB/FS mismatch ( < 0.016). In IDH-mutant_1p/19qret, the presence of AB/FS mismatch was closely related to the presence of T2/FLAIR mismatch (p = 0.014). CONCLUSIONS: CEST-derived biomarkers for amides, amines, and their ratio can help with histomolecular staging in gliomas without intense contrast enhancement. T2/FLAIR mismatch is reflected in the presence of AB/FS CEST mismatch. The AB/FS CEST mismatch identifies glioma subgroups that may have prognostic and clinical relevance

Role of diffusional kurtosis imaging in grading of brain gliomas: a protocol for systematic review and meta-analysis

INTRODUCTION: Central nervous system (CNS) gliomas are the most common primary intra-axial brain tumours and pose variable treatment response according to their grade, therefore, precise staging is mandatory. Histopathological analysis of surgical tumour samples is still deemed as the state-of-the-art staging technique for gliomas due to the moderate specificity of the available non-invasive imaging modalities. A recently evolved analysis of the tissue water diffusion properties, known as diffusional kurtosis imaging (DKI), is a dimensionless metric, which quantifies water molecules' degree of non-Gaussian diffusion, hence reflects tissue microenvironment's complexity by means of non-invasive diffusion-weighted MRI acquisitions. The objective of this systematic review and meta-analysis is to explore the performance of DKI in the presurgical grading of gliomas, both regarding the differentiation between high-grade and low-grade gliomas as well as the discrimination between gliomas and other intra-axial brain tumours. METHODS AND ANALYSIS: We will search PubMed, Medline via Ovid, Embase and Scopus in July 2018 for research studies published between January 1990 and June 2018 with no language restrictions, which have reported on the performance of DKI in diagnosing CNS gliomas. Robust inclusion/exclusion criteria will be applied for selection of eligible articles. Two authors will separately perform quality assessment according to the quality assessment of diagnostic accuracy studies-2 tool. Data will be extracted in a predesigned spreadsheet. A meta-analysis will be held using a random-effects model if substantial statistical heterogeneity is expected. The heterogeneity of studies will be evaluated, and sensitivity analyses will be conducted according to individual study quality. ETHICS AND DISSEMINATION: This work will be based on published studies; hence, it does not require institutional review board approval or ethics clearance. The results will be published in peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42018099192

Diagnostic accuracy of dynamic contrast-enhanced perfusion MRI in stratifying gliomas: A systematic review and meta-analysis

Background T1‐weighted dynamic contrast‐enhanced (DCE) perfusion magnetic resonance imaging (MRI) has been broadly utilized in the evaluation of brain tumors. We aimed at assessing the diagnostic accuracy of DCE‐MRI in discriminating between low‐grade gliomas (LGGs) and high‐grade gliomas (HGGs), between tumor recurrence and treatment‐related changes, and between primary central nervous system lymphomas (PCNSLs) and HGGs. Methods We performed this study based on the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis of Diagnostic Test Accuracy Studies criteria. We systematically surveyed studies evaluating the diagnostic accuracy of DCE‐MRI for the aforementioned entities. Meta‐analysis was conducted with the use of a random effects model. Results Twenty‐seven studies were included after screening of 2945 possible entries. We categorized the eligible studies into three groups: those utilizing DCE‐MRI to differentiate between HGGs and LGGs (14 studies, 546 patients), between recurrence and treatment‐related changes (9 studies, 298 patients) and between PCNSLs and HGGs (5 studies, 224 patients). The pooled sensitivity, specificity, and area under the curve for differentiating HGGs from LGGs were 0.93, 0.90, and 0.96, for differentiating tumor relapse from treatment‐related changes were 0.88, 0.86, and 0.89, and for differentiating PCNSLs from HGGs were 0.78, 0.81, and 0.86, respectively. Conclusions Dynamic contrast‐enhanced‐Magnetic resonance imaging is a promising noninvasive imaging method that has moderate or high accuracy in stratifying gliomas. DCE‐MRI shows high diagnostic accuracy in discriminating between HGGs and their low‐grade counterparts, and moderate diagnostic accuracy in discriminating recurrent lesions and treatment‐related changes as well as PCNSLs and HGGs

Machine learning assisted DSC-MRI radiomics as a tool for glioma classification by grade and mutation status

Background: Combining MRI techniques with machine learning methodology is rapidly gaining attention as a promising method for staging of brain gliomas. This study assesses the diagnostic value of such a framework applied to dynamic susceptibility contrast (DSC)-MRI in classifying treatment-naïve gliomas from a multi-center patients into WHO grades II-IV and across their isocitrate dehydrogenase (IDH) mutation status. Methods: Three hundred thirty-three patients from 6 tertiary centres, diagnosed histologically and molecularly with primary gliomas (IDH-mutant = 151 or IDH-wildtype = 182) were retrospectively identified. Raw DSC-MRI data was post-processed for normalised leakage-corrected relative cerebral blood volume (rCBV) maps. Shape, intensity distribution (histogram) and rotational invariant Haralick texture features over the tumour mask were extracted. Differences in extracted features across glioma grades and mutation status were tested using the Wilcoxon two-sample test. A random-forest algorithm was employed (2-fold cross-validation, 250 repeats) to predict grades or mutation status using the extracted features. Results: Shape, distribution and texture features showed significant differences across mutation status. WHO grade II-III differentiation was mostly driven by shape features while texture and intensity feature were more relevant for the III-IV separation. Increased number of features became significant when differentiating grades further apart from one another. Gliomas were correctly stratified by mutation status in 71% and by grade in 53% of the cases (87% of the gliomas grades predicted with distance less than 1). Conclusions: Despite large heterogeneity in the multi-center dataset, machine learning assisted DSC-MRI radiomics hold potential to address the inherent variability and presents a promising approach for non-invasive glioma molecular subtyping and grading

Hypertrophic Olivary Degeneration In Children: Four New Cases And A Review Of The Literature With An Emphasis On The Mri Findings

Injury to the dentato-rubro-olivary pathway causes hypertrophy and enlargement of the inferior olivary nuclei, which is called hypertrophic olivary degeneration (HOD). To date, adult cases of HOD have usually been reported, and there are only a few individual paediatric cases with limited radiological emphasis in the literature. We present the clinical and MRI findings of four new paediatric cases with HOD. Three of the patients had a posterior fossa surgery, and one did not have an identifiable cause.Wo

Effect of Patient Sex on White Matter Alterations in Unilateral Medial Temporal Lobe Epilepsy With Hippocampal Sclerosis Assessed By Diffusion Tensor Imaging

BACKGROUND AND PURPOSE: Studies shows ictal behavior and symptoms are affected by patient sex in temporal lobe epilepsy. The purpose of our study was to determine whether alterations in the WM as assessed by DTI display different patterns in male and female patients with unilateral HS. MATERIALS AND METHODS: Patients with unilateral HS were categorized as women with right HS (n = 12), men with right HS (n = 10), women with left HS (n = 12), and men with left HS (n = 10). DTI of the brain along 64 noncollinear directions was obtained from 44 patients and 37 sex-matched control participants. We used TBSS to analyze whole-brain WM. Regions with significant changes of FA and MD, and their mean FA, MD, total number of significant voxels, and asymmetry indices were determined for each group. RESULTS: All groups showed bilateral and extensive reductions of FA and elevated MD in the WM, more prominent ipsilateral to the affected hippocampus. The total number of voxels with decreased FA in patients compared with that of control participants was higher in women with right HS (24,727 vs 5,459) and in men with left HS (27,332 vs 14,013) than in their counterparts. Changes in MD associated with right HS were more extensive in both men and women (right vs left HS, women: 16,926 vs 5,458; men: 5,389 vs 4,764) than in those with left HS. In patients with right HS, the ipsilateral cingulum, uncinate fasciculus, internal and external capsules, and right acoustic radiation were involved extensively in women. CONCLUSIONS: Women and men showed different patterns in extent of WM alterations associated with HS.WoSScopu

Incomplete Endochondral Ossification Of The Otic Capsule, A Variation In Children: Evaluation Of Its Prevalence And Extent In Children With And Without Sensorineural Hearing Loss

BACKGROUND AND PURPOSE: Endochondral ossification of the otic capsule is a process that continues postnatally; hence, incomplete endochondral ossification is seen as pericochlear hypoattenuation on temporal bone CT scans of children. We determined the prevalence and extent of this entity in a large series and assessed its relation to age and underlying sensorineural hearing loss. MATERIALS AND METHODS: Initially, temporal bone CTs of 40 children with sensorineural hearing loss were retrospectively assessed and compared with those of a control group scanned for non-sensorineural hearing loss reasons to assess any difference in the prevalence or extent of incomplete endochondral ossification. Then the CT scans of 510 children (age range, 17 days to 17 years) were retrospectively reviewed, and any observed endochondral ossification areas were classified as mild, moderate, or extensive, according to their extent. RESULTS: Neither the presence nor degree of incomplete endochondral ossification had any significant correlation with the presence of sensorineural hearing loss (P = .08 and P = .1, respectively). Incomplete endochondral ossification was more frequently seen (62% of cases) than complete ossification. There was no statistically significant correlation between incomplete endochondral ossification and sex (P = .8), but an inverse correlation was found between the presence of incomplete endochondral ossification and increasing age (P < .001). Overall, mild incomplete endochondral ossification was the most frequent involvement pattern (44.4%). CONCLUSIONS: The pericochlear hypoattenuation in the otic capsule representing incomplete endochondral ossification is a normal finding in children and can be seen as a marked curvilinear hypoattenuation at younger ages in the absence of any clinical disorder.WoSScopu