Neuroimaging-Based Classification Algorithm for Predicting 1p/19q-Codeletion Status in IDH-Mutant Lower Grade Gliomas.

BACKGROUND AND PURPOSE: Isocitrate dehydrogenase (IDH)-mutant lower grade gliomas are classified as oligodendrogliomas or diffuse astrocytomas based on 1p/19q-codeletion status. We aimed to test and validate neuroradiologists' performances in predicting the codeletion status of IDH-mutant lower grade gliomas based on simple neuroimaging metrics. MATERIALS AND METHODS: One hundred two IDH-mutant lower grade gliomas with preoperative MR imaging and known 1p/19q status from The Cancer Genome Atlas composed a training dataset. Two neuroradiologists in consensus analyzed the training dataset for various imaging features: tumor texture, margins, cortical infiltration, T2-FLAIR mismatch, tumor cyst, T2* susceptibility, hydrocephalus, midline shift, maximum dimension, primary lobe, necrosis, enhancement, edema, and gliomatosis. Statistical analysis of the training data produced a multivariate classification model for codeletion prediction based on a subset of MR imaging features and patient age. To validate the classification model, 2 different independent neuroradiologists analyzed a separate cohort of 106 institutional IDH-mutant lower grade gliomas. RESULTS: Training dataset analysis produced a 2-step classification algorithm with 86.3% codeletion prediction accuracy, based on the following: 1) the presence of the T2-FLAIR mismatch sign, which was 100% predictive of noncodeleted lower grade gliomas, (n = 21); and 2) a logistic regression model based on texture, patient age, T2* susceptibility, primary lobe, and hydrocephalus. Independent validation of the classification algorithm rendered codeletion prediction accuracies of 81.1% and 79.2% in 2 independent readers. The metrics used in the algorithm were associated with moderate-substantial interreader agreement (κ = 0.56-0.79). CONCLUSIONS: We have validated a classification algorithm based on simple, reproducible neuroimaging metrics and patient age that demonstrates a moderate prediction accuracy of 1p/19q-codeletion status among IDH-mutant lower grade gliomas.

Abdominal cerebrospinal fluid pseudocyst due to infection with enterococcus faecalis. A case report.

Abdominal cerebrospinal fluid pseudocyst is a rare complication of ventriculo-peritoneal shunt occurring as a result of non-absorption of cerebrospinal fluid from the abdominal cavity due to inflammation. Usual presentations include abdominal symptoms; abdominal distention, pain, nausea, vomiting and symptoms of raised intracranial pressure like headache due to shunt dysfunction. The diagnosis may be delayed in severely handicapped patients due to poor communicability, multiple associated complications or co-morbidities. Radiological modalities are used for diagnosis as well as treatment.

Callosal holes: an unusual imaging appearance in systemic lupus erythematosus. A case report.

Systemic lupus erythematosus (SLE) has diverse imaging features. However, focal lesions in the corpus callosum are extremely rare in SLE with only few cases mentioned in the literature, with no mention of callosal holes in SLE. Callosal holes have been described as a characteristic finding in Susac syndrome and have been mentioned in Nipah virus encephalitis, Marchiafava Bignami disease and periventricular leukomalacia. We describe a case of SLE with callosal holes. The demonstration of callosal holes in this case brings the imaging appearance of SLE a step closer to that of Susac syndrome which is considered a clinically and radiologically close condition. It also adds to the list of imaging appearances of central nervous system SLE.

Cerebral venous sinus thrombosis: unusual imaging appearance. A case report.

Cerebral venous sinus thrombosis (CVST) has widely varied clinical and radiological manifestations ranging from asymptomatic minimal brain oedema to severe haemorrhagic infarcts associated with focal deficits, coma and even death. Cerebral venous sinus thrombosis presenting with lobar or subdural hematomas are rare and the cause may easily be overlooked. We present a case of CVST with an atypical radiological picture of intra-arenchymal, subdural and subarachnoid haemorrhage.

Neurosarcoidosis with intraparenchymal cystic lesions. A case report.

Sarcoidosis is a chronic multi-system granulomatous disorder of unknown etiology. Central nervous system involvement is relatively uncommon in sarcoidosis. Clinical manifestations and radiological appearances of neurosarcoidosis vary widely depending on the site and activity of the lesions. In most cases, the imaging appearance is nonspecific. We report a very rare case of extensive neurosarcoidosis with progressively enlarging cystic lesions in the right temporal lobe.

Isolated bilateral pyramidal tract lesions? An unusual case of demyelination following trauma. A case report.

This paper describes the case of a young woman who developed quadriparesis due to isolated bilateral pyramidal tract lesions suggestive of demyelination following trauma.

Magnetic Resonance Imaging in Balo's Concentric Sclerosis. A Case Report.

Concentric high signal intensity zones on T2-weighted magnetic resonance images of brain strongly suggest Balo's concentric sclerosis (BCS), a rare but recognized variant of multiple sclerosis. Differentiating BCS from multiple sclerosis or neoplasm can be difficult clinically. The pathognomonic MRI appearance can dramatically influence the course of the disease, allowing earlier diagnosis and therapy of the disease which was once considered to have an invariably fulminant and fatal course.

Bilateral subdural hemorrhage following lumbar puncture in a case of suspected meningitis. A case report.

Intracranial subdural hemorrhage is a rare complication of lumbar puncture. Caudal traction and tear of the subdural veins due to negative pressure caused by leakage of cerebrospinal fluid (CSF) following lumbar puncture (LP) is the mechanism. Prolonged headache or neurological symptoms following LP should warrant cross-sectional imaging to rule out subdural hemorrhage as it can be fatal. We report a case of subdural hemorrhage following LP in a patient with suspected meningitis and communicating hydrocephalus.

Pituitary apoplexy: a rare cause of cerebral infarction. A case report.

Pituitary apoplexy is usually the result of hemorrhagic infarction in pituitary adenoma. The clinical presentation of pituitary apoplexy varies widely and includes asymptomatic hemorrhage, classical pituitary apoplexy and even sudden death. Few cases of cerebral infarction associated with pituitary apoplexy have been reported in the literature. Pituitary apoplexy can cause narrowing of intracranial vessels by mechanical obstruction due to mass effect or by vasospasm resulting in cerebral ischemia. We report a case of pituitary apoplexy associated with cerebral infarction and the putative mechanisms.