Board Review 3 – Case 19

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 of the neck with a centrally necrotic mass in the left deep soft tissues, most likely associated with necrotic lymphadenopathy. CT images of the upper chest show tree-in-bud nodules within the upper lungs which are suspicious for infection.

The diagnosis is: mycobacterial lymphadenitis

Mycobacterial infection in the neck is most often manifested by multiple abnormal lymph nodes, often with a necrotic core. The degree of adjacent soft tissue swelling and edema is less than is typically seen with a purulent adenitis such as staphylococcus. Mycobacterium tuberculosis is the most common although there are a number of others which can cause infection, such as m. avium and m. kansasii (as in this case). The lung images are a nice clue here that the patient has a systemic infection.

Biopsy may be required to exclude malignancy, as a top differential is squamous cell carcinoma of the neck. Treatment is anti-mycobacterial drugs.

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

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 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.

https://youtu.be/nJLmYJalT8s

This case shows a CT with a soft tissue density mass extending from the frontal sinus through the outer table to the prefrontal scalp soft tissues.

The diagnosis is: frontal sinus osteomyelitis/Pott’s puffy tumor

Sometimes acute sinusitis can be complicated by adjacent osteomyelitis and bone destruction, such as in this case. The most likely location for this to happen is in the frontal sinus, when the diagnosis has the moniker “Pott’s puffy tumor”.

It is important when this happens to do an MRI of the brain to check for intracranial complications, such as meningitis, dural sinus invasion, and epidural abscess. The differential diagnosis includes malignancy (metastatic disease, lymphoma, and primary sinus malignancy), mucocele, and inflammatory diseases such as granolumatosis with polyangiitis.

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 3 – Case 9

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 mass in the left cerebellopontine angle (CP angle). It is predominantly outside of the internal auditory canal (IAC), although there is extension into the canal. It is relatively homogeneous with avid post-contrast enhancement.

The diagnosis is: meningioma

Meningiomas are the most common brain tumors (although they are extra-axial). They often have a cerebrospinal fluid (CSF) cleft around them which allow you to determine that they are extra-axial. They can calcify and cause adjacent hyperostosis of the bone.

A useful approach to CP angle masses is to first consider whether it is cystic or solid. Solid masses enhance on post-contrast imaging. If they are centered in the IAC and cause expansion, it is most likely a schwannoma. If it does not cause expansion or looks centered outside the IAC, think about meningioma.

Board Review Cases – Head and Neck

This playlist is a collection of only the head and neck imaging board review cases on this site. This includes pathologies such as head and neck cancer and skull base abnormalities.

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.

 

CT (computed tomography) face radiology search pattern

When you start taking call as a radiology resident, a common test you are going to encounter is a maxillofacial CT, or face CT. This is especially true if you are taking call at a level 1 or level 2 trauma center. A lot of times, this is done in conjunction with a head and/or cervical spine CT. This is an extremely common test in the setting of trauma, including assault and car accidents (MVA or MVC). The key in these settings is to rule out a significant fracture or soft tissue injury to the face.

Because there are a lot of structures, it is important to have a useful search pattern. Reconstructions, especially the coronal reconstruction, are key when interpreting CT of the face. These allow you to see key structures that are parallel to the slice plane on axial images. Symmetry is extremely helpful, as the left should match the right. Additionally, making sure all the fat and fascia planes are clean is very useful.

This video will walk you through a step-by-step approach to evaluating a CT of the face. I recommend a pattern where you start with the coronals at the cranial (top) part of the image, and then work your way down. In this way, you can look at the brain, orbits, sinuses, palate, mandible, and so forth, minimizing the risk of missing a significant finding. Then you can repeat the pattern with the axial images. Finally, the sagittal images are a nice troubleshooting tool, especially for the mandible and cervical spine. As you practice, you will find you can move more quickly through your search without necessarily focusing on each individual element for too long.

The level of this lecture is appropriate for medical students, junior residents, and trainees in other specialties who have an interest in neuroradiology or may be involved with patients with facial injuries and other abnormalities.

 

See this and other videos on our Youtube channel.

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 2

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 hearing loss some thickening of the bone in the external auditory canals. It is bilaterally symmetric and causes severe EAC narrowing.

The diagnosis is: surfer’s ear, or exostosis of the external auditory canal.

Board Review 2 – Case 1

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 mass in the right cerebellopontine angle and internal auditory canal. The differential for these masses includes schwannoma, meningioma, arachnoid cyst, and epidermoid. The key to differentiating this mass from others are that it is solid, centered in the internal auditory canal, and has a few areas of cystic degeneration or necrosis.

The diagnosis is: vestibular schwannoma