Deep neural network to locate and segment brain tumors outperformed the expert technicians who created the training data.

Purpose: Deep learning (DL) algorithms have shown promising results for brain tumor segmentation in MRI. However, validation is required prior to routine clinical use. We report the first randomized and blinded comparison of DL and trained technician segmentations. Approach: We compiled a multi-institutional database of 741 pretreatment MRI exams. Each contained a postcontrast T1-weighted exam, a T2-weighted fluid-attenuated inversion recovery exam, and at least one technician-derived tumor segmentation. The database included 729 unique patients (470 males and 259 females). Of these exams, 641 were used for training the DL system, and 100 were reserved for testing. We developed a platform to enable qualitative, blinded, controlled assessment of lesion segmentations made by technicians and the DL method. On this platform, 20 neuroradiologists performed 400 side-by-side comparisons of segmentations on 100 test cases. They scored each segmentation between 0 (poor) and 10 (perfect). Agreement between segmentations from technicians and the DL method was also evaluated quantitatively using the Dice coefficient, which produces values between 0 (no overlap) and 1 (perfect overlap). Results: The neuroradiologists gave technician and DL segmentations mean scores of 6.97 and 7.31, respectively ( p < 0.00007 ). The DL method achieved a mean Dice coefficient of 0.87 on the test cases. Conclusions: This was the first objective comparison of automated and human segmentation using a blinded controlled assessment study. Our DL system learned to outperform its "human teachers" and produced output that was better, on average, than its training data.

Disseminated High-grade Glioma in a Long-term Survivor of Medulloblastoma: Implications and Management of Radiation-induced Malignancies.

We describe a gentleman diagnosed with a posterior fossa medulloblastoma in 1998, successfully treated with craniospinal radiation therapy (RT) and posterior fossa RT boost, followed by 12 months of adjuvant chemotherapy. Nineteen years later, at the age of 28, the patient presented with multiple cranial neuropathies and was found to have disseminated high-grade glioma with leptomeningeal dissemination. In addition to the salient features of this case, we provide a brief review of RT-induced malignancies and the need for further research regarding surveillance and prevention strategies.

Normal Variant Occipital Pneumatization.

OBJECTIVE: Evaluate prevalence and pattern of occipital pneumatization (OP). PATIENTS: Individuals with imaging evidence of OP on computed tomography (CT). INTERVENTION(S): High resolution CT scans of the temporal bone. MAIN OUTCOME MEASURE: The prevalence and pattern of OP on 1000 CT scans performed at a large academic healthcare system. RESULTS: OP had a prevalence of 11.8% (n = 118) while occipital condyle pneumatization occurred in only 0.3%. Occipital air cells were right-sided in 27.1% (n = 32), left-sided in 51.7% (n = 61), and bilateral in 21.2% (n = 25), and OP was contiguous with the occipitomastoid suture. In cases of unilateral OP, the contralateral jugular foramen demonstrated relative enlargement (p = 0.006), but a direct association could not be established. CONCLUSIONS: The occipital bone is an accessory site of skull base pneumatization in 11.8% of the population undergoing temporal bone CT, while air cell extension into the occipital condyle occurs more rarely. These occipital air cells have a left-sided predilection and are always in direct proximity to the occipitomastoid suture, suggesting developmental egress from the mastoid. OP is a normal variant and lacks features of craniocervical pneumatization, which is a rare disorder.

Magnetic Resonance Imaging Assessment of Vascular Contact of the Facial Nerve in the Asymptomatic Patient.

Objective The objective of this study was to determine the prevalence of facial nerve vascular contact on magnetic resonance imaging (MRI) in patients without hemifacial spasm (HFS). Study Design Our radiology database was queried to identify consecutive adult patients without a history of HFS, intracranial tumor, brain radiation therapy, intracranial surgery, traumatic brain injury, or trigeminal nerve vascular compression. One hundred high-resolution MRIs of the posterior fossa were independently reviewed by two neuroradiologists for facial nerve vascular contact (200 sides). Main Outcome Measures The prevalence of vascular nerve contact in the non-HFS patient, the location of contact along the facial nerve, the culprit vessel, and severity of compression was recorded. Results The presence of vascular contact in the non-HFS patient may be as high as 53%. It is typically mild to moderate in severity, most commonly involves the cisternal portion, and usually caused by the anterior inferior cerebellar artery. Conclusion Vascular contact of the facial nerve is frequently identified in asymptomatic individuals but tends to be more peripheral and mild compared with previous descriptions of neurovascular contact in HFS patients. These results should be considered in assessing the candidacy of HFS patients for microvascular decompression.

The role of digital subtraction myelography in the diagnosis and localization of spontaneous spinal CSF leaks.

OBJECTIVE: The objective of our study was to review the clinical utility of digital subtraction myelography for the diagnosis of spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH) and those with superficial siderosis. MATERIALS AND METHODS: Procedure logs from 2007 to 2011 were reviewed to identify cases in which digital subtraction myelography was performed to diagnose spinal CSF leaks. Electronic medical records were reviewed to obtain information regarding diagnosis and outcome. For patients to be included in the study, preprocedural spinal MRI had to show an extradural fluid collection spanning more than one vertebral level and postmyelographic CT had to confirm the presence of an active CSF leak. If digital subtraction myelography successfully showed the site of the CSF leak, the location was documented. RESULTS: Eleven patients (seven men and four women; mean age, 49.0 years) underwent digital subtraction myelography during the study period. Six patients had SIH and five patients had superficial siderosis. The extradural fluid collection on spinal MRI averaged a length of 15.5 vertebral levels. Digital subtraction myelography successfully showed the site of the CSF leak in nine of the 11 patients, and all of the dural tears were located in the thoracic spine between T3 and T11. CONCLUSION: Digital subtraction myelography is a valuable diagnostic tool for the localization of rapid spinal CSF leaks and should be considered in patients who are clinically suspected to have a dural tear that is accompanied by a longitudinally extensive extradural fluid collection on spinal MRI.

Refractory headaches due to multilevel thoracic cerebrospinal fluid leaks.

BACKGROUND: Spontaneous cerebrospinal fluid leak is a well-documented cause of postural headache. We report a medically refractory headache due to multilevel thoracic cerebrospinal fluid leaks. CASE REPORT: A 44-year-old male with an acute onset of postural headache failed to respond to bed rest, hydration, and analgesics. Magnetic resonance imaging demonstrated a large cerebrospinal fluid leak centered at the right T4 and left T11 to 12 levels, with bony pathology evident at the lower thoracic level. Lumbar (L4 to 5) and computed tomography guided T4 to 5 level epidural blood patches provided minimal pain relief. Percutaneous epidural fibrin glue injection at T4 followed by a repeat computed tomography guided epidural blood patch led to significant but incomplete symptom relief. Subsequent imaging demonstrated persistent fluid at the T11 to 12 level. Fibrin glue and epidural blood patches at this level reduced but did not eliminate the leak and residual symptoms. Extensive corrective surgery was offered but declined by the patient. CONCLUSION: Treatment of multifocal cerebrospinal fluid leaks can be challenging, particularly when at least part of the underlying etiology is fixed structural bony pathology.

Metastatic prostate carcinoma mimicking meningioma: case report and review of the literature.

BACKGROUND: Intracranial dural-based lesions can be due to benign or malignant processes. Imaging characteristics cannot always discern between different pathologic conditions. A thorough clinical evaluation may reveal likely diagnostic possibilities. However, in certain cases, the etiology of the underlying lesion may require biopsy or resection to appropriately treat the patient. REVIEW SUMMARY: We report the case of a large dural-based adenocarcinoma of the prostate clinically and radiographically mimicking a meningioma. We review the history and physical evaluation of the patient and subsequent treatment and response. We discuss the implications of dural-based intracranial lesions in patients with prostate cancer and review the literature of dural metastases, including the pathogenesis, tumor types, and clinical presentations. CONCLUSION: The differential diagnosis of dural-based lesions in the brain varies from incidental and benign to symptomatic and malignant. Careful vigilance in patients with a history of cancer and presenting with new symptoms or imaging evidence of dural-based lesions is critically important to provide timely intervention.

Carotid pseudostring sign from vasa vasorum collaterals.

OBJECTIVE: To describe the spectral and color Doppler imaging findings in 2 cases of internal carotid artery occlusion with vasa vasorum collateral flow, which we term the "pseudostring sign." METHODS: Spectral and color Doppler imaging findings in both cases were reviewed. Magnetic resonance angiography in 2 cases and conventional angiography in 1 case were also reviewed. RESULTS: Both patients had color Doppler images showing that the internal carotid artery was a narrow, stringlike vessel with arterial flow that had normal spectral Doppler features (velocity < 125 cm/s with a normal waveform). Magnetic resonance angiography in 1 patient showed total occlusion of the proximal internal carotid artery with patent vasa vasorum collaterals reconstituting the lumen distally. In the second patient, magnetic resonance angiography showed total occlusion of the proximal internal carotid artery, and conventional angiography showed proximal occlusion with collateral flow through the vasa vasorum. CONCLUSION: Proximal internal carotid artery occlusion with vasa vasorum collateral flow should be considered when color Doppler imaging shows a seemingly narrow internal carotid artery with tortuosity and normal spectral Doppler features. Patients with these features should not undergo carotid endarterectomy directly on the basis of only the Doppler findings.