Board Review 1 – Case 17

Posted on May 28, 2018January 15, 2019 by Brent Weinberg, MD

Board Review 1 – Case 17

Neuroradiology board review. This lecture is geared towards the ABR core exam for residents, but it would be useful for review for the ABR certifying exam or certificate of added qualification (CAQ) exam for neuroradiology.

More description and the answer (spoiler!) are seen below the video.

In this patient with trigeminal neuralgia, there is a mass in the left cerebellopontine angle which is causing mass effect on the pons and cerebellar peduncle. Its imaging appearance is close to that of CSF on all sequences except diffusion weighted imaging (DWI), on which it is bright.

Lesions of the cerebellopontine angle can be cystic or solid. Cystic appearing masses include arachnoid cysts and epidermoid.

The diagnosis is: epidermoid

Epidermoids of the cerebellopontine angle are inclusion cysts which contain secretions which are bright on DWI, distinguishing them from arachnoid cysts. They tend to have minimal if any enhancement.

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Board Review 1 – Case 16

Posted on May 28, 2018December 18, 2018 by Brent Weinberg, MD

Board Review 1 – Case 16

More description and the answer (spoiler!) are seen below the video.

This case shows a solitary lesion with central T2 hyperintensity and surrounding siderosis (dark on T2). The area shows no real enhancement, although there is a linear branching structure adjacent to the lesion

The diagnosis is: cerebral cavernous malformation

Cerebral cavernous malformations are angiographically occult vascular malformations which consist of clusters of abnormal capillaries without a shunt. Their characteristic appearance is a rim of hemosiderin which may take on the appearance of a popped popcorn kernel. Developmental venous anomalies (DVAs), are often seen with isolated cavernous malformations.

Other times, patients may have multiple lesions which can be associated with familial syndromes.

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Board Review 1 – Case 15

Posted on May 28, 2018December 18, 2018 by Brent Weinberg, MD

Board Review 1 – Case 15

More description and the answer (spoiler!) are seen below the video.

This case starts with a CT showing bilateral temporal bone fractures after a major trauma. There are a number of potential complications of temporal bone fractures, but on the left the ossicles are no longer in alignment.

The diagnosis is: ossicular dissociation from trauma

Fractures of the temporal bone can cause a number of complications, including meningitis, conductive hearing loss, and facial nerve injury. This shows dislocation of the malleus and incus on the left. Fractures should be classified by whether they involve the otic capsule or spare the otic capsule.

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Board Review 1 – Case 14

Posted on May 28, 2018December 18, 2018 by Brent Weinberg, MD

Board Review 1 – Case 14

More description and the answer (spoiler!) are seen below the video.

This case starts with a CT showing a mass in the right ethmoid air cells. There is dehiscence of the adjacent cribriform plate. MRI with contrast shows a mass predominantly in the ethmoid air cells, although there is intracranial extension with abnormal dural enhancement.

The diagnosis is: esthesioneuroblastoma

Esthesioneuroblastomas are neuroblastomas of the olfactory nerves. Their classic description is a mixed sinus and intracranial mass which sometimes has an intracranial cyst. The main differential diagnostic consideration is a squamous cell carcinoma of the sinuses.

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Board Review 1 – Case 13

Posted on May 28, 2018December 18, 2018 by Brent Weinberg, MD

Board Review 1 – Case 13

More description and the answer (spoiler!) are seen below the video.

This case shows a hyperdense mass in the left posterior nasal passages. There is expansion of the left sphenopalatine foramen. In a relatively young patient, there is really only one diagnostic consideration.

The diagnosis is: Juvenile nasal angiofibroma (JNA)

Juvenile nasal angiofibromas are masses that arise in the sphenopalatine foramen in young boys. They are extremely vascular lesions and are typically treated by embolization of branches of the external carotid artery which supply the mass prior to resection.

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Board Review 1 – Case 12

Posted on May 28, 2018December 18, 2018 by Brent Weinberg, MD

Board Review 1 – Case 12

More description and the answer (spoiler!) are seen below the video.

In this case, there are curvilinear calcifications which follow the cortex in the right cerebral hemisphere on CT. On MRI, there is atrophy of the right cerebral hemisphere with abnormal veins coursing through the deep white matter of the right cerebral hemisphere. On contrast enhanced images, there is avid enhancement of the right hemisphere leptomeninges.

The diagnosis is: Sturge-Weber syndrome

Sturge-Weber syndrome is a variant in which normal cortical vessels fail to form, and the hemisphere is drained by abnormal mesenchymal veins which course through the cerebral hemisphere. Classic imaging findings include cortical calcifications of one hemisphere.

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Board Review 1 – Case 11

Posted on May 28, 2018December 18, 2018 by Brent Weinberg, MD

Board Review 1 – Case 11

More description and the answer (spoiler!) are seen below the video.

This case shows a hyperdense structure in the third ventricle near the foramen of Monro on CT of the head. There is mild associated hydrocephalus. Findings on MRI confirm the presence of a mass which is well demarcated and hyperintense on T1 and T2 weighted imaging with minimal enhancement.

The diagnosis is: Colloid cyst

A colloid cyst is a well demarcated, benign mass in the third ventricle near the foramen of Monro. These masses make patients susceptible to rapid onset hydrocephalus which can be fatal, which necessitates their resection.

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Board Review 1 – Case 10

Posted on May 20, 2018December 11, 2018 by Brent Weinberg, MD

Board Review 1 – Case 10

More description and the answer (spoiler!) are seen below the video.

This case shows bilateral areas of reduced diffusion in the medial thalami, concerning for infarcts. When the bilateral thalami are involved by infarcts, the differential includes artery of Percheron infarct, basilar tip occlusion, and venous infarct.

The diagnosis is: artery of Percheron infarct

The artery of Percheron is a variant in which the thalamic perforators from the PCA are supplied from a trunk from one P1. When this trunk is occluded, bilateral thalamic infarcts can occur.

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Board Review 1 – Case 9

Posted on May 20, 2018December 11, 2018 by Brent Weinberg, MD

Board Review 1 – Case 9

More description and the answer (spoiler!) are seen below the video.

This case shows multiple areas of intracranial edema with post-contrast enhancement in a patient with HIV. The key to the diagnosis in this case is the appearance on diffusion weighted imaging (bright) and ADC, consistent with centrally reduced diffusion.

The diagnosis is: intracranial abscess

Intracranial abscesses are parenchymal collections of pus within the brain. Their key feature is peripheral enhancement with centrally reduced diffusion. They are more common in immune suppressed patients.

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Board Review 1 – Case 8

Posted on May 20, 2018December 11, 2018 by Brent Weinberg, MD

Board Review 1 – Case 8

More description and the answer (spoiler!) are seen below the video.

This case shows a right sided hyperdense extraaxial collection on a CT. This collection crosses sutures and has a crescent shape, suggesting a subdural location.

The diagnosis is: subdural hematoma

Subdural hematomas are extraaxial collections of blood which can be spontaneous or seen after trauma. Most commonly they are caused by bridging subdural veins. They have a high mortality and can sometimes require evacuation.

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