Board Review 3 – Case 18

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.

This case shows a patient with Horner’s syndrome who has subtle narrowing of the extracranial internal carotid artery on the left. On T1 fat-saturated imaging, there is a crescent of methemoglobin within the medial aspect of the vessel wall.

The diagnosis is: internal carotid artery dissection

Anytime a patient, particularly a young patient, has acute onset of neurologic symptoms, arterial dissection has to be on the differential. When it is accompanied by a Horner’s syndrome, internal carotid dissection is high on the differential because the sympathetic fibers for they eye travel alongside the carotid artery.

Arterial dissection is injury to the walls of the vessel. Most often the innermost layer, the intima, is separated from the deeper layers, the media and adventitia. It can be associated with a visible flap of lifted intima in the vessel and a portion of the vessel which is not carrying blood, a false lumen. When the vessel is disrupted enough to have visible dilation, this is a pseudoaneurysm.

In this case, the MR angiogram findings are quite subtle, but the key is the T1 fat-saturated images, which show a crescent of methemoglobin in the vessel wall. Fat saturation is required to differentiate this hyperintensity from the adjacent fat in the neck, which is also hyperintense.

Arterial dissection is associated with a variety of conditions, including trauma, fibromuscular dysplasia, vasculitis, and connective tissue disorders.

Board Review 3 – Case 15

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.

This case shows an avidly enhancing mass in the left neck which has the appearance of a tangle of vessels. These images are from a CT angiogram and the enhancement is very similar to the vascular structures, so you are likely looking at a vascular abnormality.

The diagnosis is: soft tissue arteriovenous malformation (AVM)

In this case, the abnormality has a lot of arterial enhancing components and there are associated abnormal veins, so there is a shunt between the arterial and venous structures, making this an AVM.

When looking at soft tissue vascular malformations, there is a relatively simple algorithm you can go through. If a mass has a soft tissue component, then it is a hemangioma because it has a proliferative mass component. If it has high flow components (like in this case), it is an arteriovenous malformation or AVM. If it has multiple cystic regions with fluid levels, it is a lymphatic malformation. The remaining abnormalities with slow flow vessels are venous malformations. There is a lot of overlap, with many vascular malformations having multiple components.

The treatment of these lesions is most commonly surgery, often with embolization before to reduce the amount of bleeding during resection. Sclerotherapy (or injection of a sclerotic agent through the skin) is usually not an option because these are high flow lesions and the agent will disperse to other areas in the body.

Board Review 2 – Case 14

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.

This case shows a patient with a new neurologic deficit and a relatively normal noncontrast head CT. Perfusion, on the other hand, shows an area of decreased CBV, increased MTT, and increased Tmax in the posterior aspect of the left middle cerebral artery (MCA) distribution. There is an associated vessel occlusion on CT angiogram.

The diagnosis is: cerebral ischemia (stroke)

This patient has an area of ischemia in the left MCA territory. Because the CBV is relatively maintained, this tissue is mostly considered penumbra. When there is a significant decrease in volume and flow, it is considered core infarct that is not likely to recover.

Board Review Cases – Vascular

This playlist is a collection of only the vascular imaging board review cases on this site. This includes primary vascular pathologies, such as stroke and vascular malformations

These cases are geared towards preparation for the radiology resident ABR core exam, although similar material is used for the ABR certifying exam general and neuroradiology sections as well as neuroradiology CAQ. The format of this playlist is case-based. Each case consists of a series of images followed by 1 or 2 questions. The first question is usually to name the diagnosis, while the second is a multiple choice question to test deeper understanding of the specific condition. Try to get the diagnosis before you see the second questions.

 

Board Review 2 – Case 6

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.

This case shows a CT with hyperdense blood tracking in the left basal ganglia and thalamus. Although the patient is relatively young, the location is strongly suspicious for hypertensive hemorrhage. Further evaluation for underlying causes, such as a vascular malformation or tumor, is warranted with vascular imaging (such as CTA) and MRI.

The diagnosis is: hypertensive hemorrhage

Board Review 2 – Case 5

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.

This case shows a patient with headache. Images are from an MR angiogram of the neck. The first few images show absence of filling of the left vertebral artery. This could theoretically be from atherosclerotic disease or thrombosis, but there is filling on a contrast enhanced MRA of the neck. This is because the flow in the vertebral artery is reversed in the setting of occlusion of the proximal subclavian artery.

The diagnosis is: subclavian steal

Board Review 2 – Case 3

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.

This case shows a patient with a coagulation disorder and new neurologic symptoms. FLAIR images show hyperintensity in the right transverse and sigmoid sinus. The abnormality is confirmed on magnetic resonance venogram, which shows absence of flow in that region. There is a filling defect on postcontrast imaging.

The diagnosis is: dural sinus thrombosis

Board Review 1 – Case 6

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.

This case is a young postpartum patient with seizure and somnolence. The MRI shows FLAIR hyperintense white matter abnormalities in a predominantly posterior distribution. There is likely a small amount of subarachnoid hemorrhage.

The diagnosis is: posterior reversible encephalopathy syndrome, or PRES.

PRES has several names, including acute hypertensive encephalopathy, although this is also misleading because there are several causes, including hypertension and many medications. It is a primary disorder of vasoregulation, with edema occurring in subcortical white matter.