A multi-institutional meningioma MRI dataset for automated multi-sequence image segmentation.

Meningiomas are the most common primary intracranial tumors and can be associated with significant morbidity and mortality. Radiologists, neurosurgeons, neuro-oncologists, and radiation oncologists rely on brain MRI for diagnosis, treatment planning, and longitudinal treatment monitoring. However, automated, objective, and quantitative tools for non-invasive assessment of meningiomas on multi-sequence MR images are not available. Here we present the BraTS Pre-operative Meningioma Dataset, as the largest multi-institutional expert annotated multilabel meningioma multi-sequence MR image dataset to date. This dataset includes 1,141 multi-sequence MR images from six sites, each with four structural MRI sequences (T2-, T2/FLAIR-, pre-contrast T1-, and post-contrast T1-weighted) accompanied by expert manually refined segmentations of three distinct meningioma sub-compartments: enhancing tumor, non-enhancing tumor, and surrounding non-enhancing T2/FLAIR hyperintensity. Basic demographic data are provided including age at time of initial imaging, sex, and CNS WHO grade. The goal of releasing this dataset is to facilitate the development of automated computational methods for meningioma segmentation and expedite their incorporation into clinical practice, ultimately targeting improvement in the care of meningioma patients.

Differential Diagnosis of Tumor-like Brain Lesions.

Purpose of Review: Tumor-like brain lesions are rare and commonly suggest a neoplastic etiology. Failure to rapidly identify non-neoplastic causes can lead to increased morbidity and mortality. In this review, we describe 10 patients who presented with atypical, non-neoplastic tumor-like brain lesions in which brain biopsy was essential for a correct diagnosis and treatment. Recent Findings: There has been increasing recognition of autoimmune conditions affecting the nervous system, and many of those diseases can cause tumor-like brain lesions. Currently available reports of non-neoplastic tumor-like brain lesions are scarce. Most case series focus on tumefactive demyelinating lesions, and a comprehensive review including other neuroimmunological conditions such as CNS vasculitis, neurosarcoidosis, histiocytic and infectious etiologies is lacking. Summary: We review the literature on tumor-like brain lesions intending to increase the awareness and differential diagnosis of non-neoplastic brain tumor mimics. We advocate for earlier brain biopsies, which, in our case series, significantly changed diagnosis, management, and outcomes.

High resolution 3D magnetic resonance imaging of Gruber's ligament: a pilot study.

INTRODUCTION: Gruber's ligament (GL), a surgical landmark, extends from the lateral upper clivus to the petrous apex (PA), forming the superior boundary of Dorello's canal (DC). It overlies the interdural segment of the abducens nerve (CN VI). High-resolution 3D skull base MRI (SB-MRI) demonstrates anatomic details visible to the surgeon, but not well seen on traditional cross-sectional imaging. The aim of this study was to demonstrate visualization of the GL and its relationship to CN VI utilizing contrast enhanced high-resolution SB-MRI. METHODS: Two neuroradiologists retrospectively reviewed in consensus the SB-MRIs of 27 skull base sides, among 14 patients. GL detection rate, confidence of detection, and GL length were recorded. When GL was successfully identified, the position of the interdural segment of CN VI within DC was recorded. RESULTS: GL was readily identified in 16 skull base sides (59%), identified with some difficulty in 2 skull base sides (7%), and failed to be identified in 9 skull base sides (33%). The mean GL length was 7.1 mm (4.5-9.3 mm). Among the 18 cases where GL was successfully identified, CN VI was readily identified in all cases (100%), coursing the lateral third of DC in 72% of sides, and middle third in the remaining 28% of sides. CONCLUSION: GL can be identified in approximately two-thirds of cases utilizing 3D high resolution SB-MRI. CN VI passes most commonly along the lateral third of DC. This is the first report demonstrating visualization of GL and its relation to CN VI, on imaging.

First-Line Stent Retriever versus Direct Aspiration for Acute Basilar Artery Occlusions: A Systematic Review and Meta-analysis.

BACKGROUND: Mechanical thrombectomy (MT) for anterior circulation stroke has been proven to be highly effective. In comparison, MT for basilar artery occlusion (BAO) continues to lack definitive evidence of efficacy. The main MT modalities are stent retriever (SR) and direct aspiration (DA). Several studies have been published comparing the 2 approaches. OBJECTIVE: We sought to directly compare and synthesize safety and efficacy outcomes with SR versus DA for acute BAO. METHODS: A systematic review and meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: Overall, 8 studies comprising 693 patients with BAO were included (SR: 457; DA: 236). The SR group was associated with statistically significant lower odds of modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 (odds ratio [OR]: 0.54; 95% confidence interval [CI]: 0.31-0.94) and mTICI3 (OR: 0.47; 95% CI: 0.23-0.95) compared with DA. Favorable outcome rates were similar between the 2 groups (OR: 0.83; 95% CI: 0.60-1.16). The rates of symptomatic intracerebral hemorrhage (OR: 3.57; 95% CI: 0.75-16.95), subarachnoid hemorrhage (SAH) (OR: 4.71; 95% CI: 0.82-26.90), and vessel perforation (OR: 2.64; 95% CI: 0.43-16.33) were higher in the SR group, but statistical significance was not reached. The rates of 90-day mortality were similar between the 2 groups (OR: 1.07; 95% CI: 0.67-1.70). Procedure duration was significantly shorter when DA was used compared with SR (weighted mean difference: 26.10 minutes; 95% CI: 13.28-38.92). CONCLUSIONS: SR is associated with statistically significant lower odds of mTICI 2b/3 and mTICI 3 recanalization rates compared with DA. SR appears to be associated with a higher complication rate, but significance was not reached.

Development and evaluation of a high performance T1-weighted brain template for use in studies on older adults.

Τhe accuracy of template-based neuroimaging investigations depends on the template's image quality and representativeness of the individuals under study. Yet a thorough, quantitative investigation of how available standardized and study-specific T1-weighted templates perform in studies on older adults has not been conducted. The purpose of this work was to construct a high-quality standardized T1-weighted template specifically designed for the older adult brain, and systematically compare the new template to several other standardized and study-specific templates in terms of image quality, performance in spatial normalization of older adult data and detection of small inter-group morphometric differences, and representativeness of the older adult brain. The new template was constructed with state-of-the-art spatial normalization of high-quality data from 222 older adults. It was shown that the new template (a) exhibited high image sharpness, (b) provided higher inter-subject spatial normalization accuracy and (c) allowed detection of smaller inter-group morphometric differences compared to other standardized templates, (d) had similar performance to that of study-specific templates constructed with the same methodology, and (e) was highly representative of the older adult brain.

Segmental Imaging of the Trochlear Nerve: Anatomic and Pathologic Considerations.

BACKGROUND: The trochlear nerve (the fourth cranial nerve) is the only cranial nerve that arises from the dorsal aspect of the midbrain. The nerve has a lengthy course making it highly susceptible to injury. It is also the smallest cranial nerve and is often difficult to identify on neuroimaging. EVIDENCE ACQUISITION: High-resolution 3-dimensional skull base MRI allows for submillimeter isotropic acquisition and is optimal for cranial nerve evaluation. In this text, the detailed anatomy of the fourth cranial nerve applicable to imaging will be reviewed. RESULTS: Detailed anatomic knowledge of each segment of the trochlear nerve is necessary in patients with trochlear nerve palsy. A systematic approach to identification and assessment of each trochlear nerve segment is essential. Pathologic cases are provided for each segment. CONCLUSIONS: A segmental approach to high-resolution 3-dimensional MRI for the study of the trochlear nerve is suggested.

Predictors for the extent of pial collateral recruitment in acute ischemic stroke.

BACKGROUND: Pial arterioles can provide a variable degree of collateral flow to ischemic vascular territories during acute ischemic stroke. This study sought to identify predictive factors of the degree of pial collateral recruitment in acute ischemic stroke. METHODS: Clinical information and arteriograms from 62 consecutive patients with stroke due to either middle cerebral artery (MCA) M1 segment or internal carotid artery (ICA) terminus occlusion within 6 h following symptom onset were retrospectively reviewed. Pial collaterals were defined based on the extent of reconstitution of the MCA territory. Patients with slow antegrade flow distal to the occlusion site were excluded and no anesthetics were used prior or during angiography. Results were analyzed using multivariate nominal logistic regression. RESULTS: Better pial collateral recruitment was associated with proximal MCA versus ICA terminus occlusion (p = 0.005; odds ratio (OR) = 9.3; 95% confidence interval (CI), 2.16-53.3), lower presenting National Institutes of Health Stroke Scale Score (NIHSSS) (p = 0.023; OR = 6.51; 95% CI, 1.49-41.7), and lower diastolic blood pressure (p = 0.0411; OR = 5.05; 95% CI, 1.20-29.2). Age, gender, symptom duration, diabetes, laterality, systolic blood pressure, glucose level, hematocrit, platelet level, and white blood cell count at presentation were not found to have a statistically significant association with pial collateral recruitment. CONCLUSIONS: Extent of pial collateral recruitment is strongly associated with the occlusion site (MCA M1 segment versus ICA terminus) and less strongly associated with presenting NIHSSS and diastolic blood pressure.

Acute Headache in the Emergency Setting.

Acute headache is a common symptom and is reported by approximately 2%-4% of patients who present to the emergency department. Many abnormalities manifest with headache as the first symptom, and it is crucial to obtain a patient's complete clinical history for correct diagnosis. Headache onset, duration, and severity; risk factors such as hypertension, immunosuppression, or malignancy; and the presence of focal neurologic deficits or systemic symptoms may aid the radiologist in deciding whether imaging is appropriate and which modality to choose. Imaging findings are more likely to be abnormal in patients with a "thunderclap" headache than in those with headaches of lesser severity. The causes of headache in the emergency setting are various. They may manifest at imaging as subarachnoid hemorrhage (ruptured aneurysm, reversible vasoconstriction syndrome, or pituitary apoplexy), parenchymal hemorrhage (hypertension, ruptured arteriovenous malformation, cerebral amyloid angiopathy, dural arteriovenous fistula, or sinus thrombosis), or parenchymal edema (posterior reversible encephalopathy syndrome, reversible cerebral vasoconstriction syndrome, sinus thrombosis, or encephalitis). Alterations in intracranial pressure that are related to idiopathic intracranial hypertension or spontaneous intracranial hypotension and prior lumbar puncture or epidural injection may manifest with specific imaging findings. With accumulating knowledge of disease pathophysiology, radiologists have started to play a more central role in making the correct diagnosis. This article reviews multiple causes of acute headache and their characteristic appearances at multimodality imaging and familiarizes the reader with current concepts in imaging.Online supplemental material is available for this article.©RSNA, 2019.

Toxic-Metabolic Neurologic Disorders in Children: A Neuroimaging Review.

There are multiple causes of neurotoxicity in children including medications, extrinsic toxins and insults, illicit drugs, built up of toxic metabolites due to genetic or acquired disorders, and metabolic abnormalities. The review is centered on causes of neurotoxicity affecting the pediatric brain and producing typical and easily recognized imaging manifestations. Early identification of common and less common imaging findings may point toward the correct direction, and may facilitate early diagnosis and institution of appropriate treatment to reverse or at least limit the injury to the developing brain. Two common imaging patterns of neurotoxicity in children are the posterior reversible encephalopathy syndrome and acute toxic leukoencephalopathy that are usually related to chemotherapy and immunosuppression for common pediatric malignancies. Another well-described imaging pattern of injury in children involves reversible splenial lesions with or without associated white matter abnormalities. Multiple additional extrinsic causes of neurotoxicity are presented including radiation and chemoradiation, various medications and treatment regimens, poisoning, illicit drug use or accidental exposure, and the respective characteristic neuroimaging findings are highlighted. Intrinsic neurotoxicity may occur in the setting of inborn errors of metabolism or acquired progressive organ failure leading to build up of toxic metabolites. Additional intrinsic causes of neurotoxicity include metabolic derangements and characteristic imaging findings in all instances are reviewed. The goal of the article is to enhance familiarity of neurologists and neuroradiologists with the imaging appearance of common and less common toxic insults to the pediatric brain.

Lesions in the Splenium of the Corpus Callosum on MRI in Children: A Review.

A wide variety of conditions may involve the splenium of the corpus callosum on magnetic resonance imaging in children. A single cause may present with different patterns of splenial involvement, and multiple diseases may have similar imaging findings. Keeping this limitation in mind, the goal of this text is to assist in the diagnostic process of pediatric neurological diseases that are characterized by prominent involvement of the splenium of the corpus callosum on imaging. The various pathologies will be reviewed and categorized based on etiology, reversibility, and pattern of additional or associated findings. Transient splenial lesions in children are an uncommon radiologic finding of unknown etiology in a long list of conditions that may present with altered consciousness, and it usually carries a favorable prognosis. The discussion continues with the presentation of diseases inflicting irreversible damage on the splenium. Familiarity with the various causes implicated in splenial injury may assist in the formulation of differential diagnosis in the appropriate clinical setting using an easily recognizable imaging finding.

Imaging evaluation of trigeminal neuralgia.

Trigeminal neuralgia is a debilitating pain syndrome in the sensory distribution of the trigeminal nerve. Compression of the cisternal segment of the trigeminal nerve by a vessel, usually an artery, is considered the most common cause of trigeminal neuralgia. A number of additional lesions may affect the trigeminal nerve anywhere along its course from the trigeminal nuclei to the most peripheral branches to cause facial pain. Relevant differential considerations are reviewed starting proximally at the level of the brainstem.