Head and Neck Radiology

Question 1

Cholesterol granuloma radiologic findings

Answer 1

Expansile unilocular cystic lesion most commonly in the petrous apex.

CT shows a well circumscribed unilocular expansile lesion with sclerotic smooth margin, sharp transition zone.

MRI shows hyperintense T1 and T2 lesion that does not enhance or have diffusion abnormality

Question 2

Cholesteatoma radiologic findings

Answer 2

CT: soft tissue mass in middle ear cavity causing bony or ossicular erosion. Small early cholesteatoma may not demonstrate this. Mass in Prussak’s space will cause erosion of the scutum.

MRI: Hypointense signal on T1, hyperintense signal on T2 with no enhancement. Demonstrate restricted diffusion

Question 3

Facial nerve neuritis radiologic findings

Answer 3

Asymmetric and increased enhancement of the facial nerve compared to the normal oppose side seen on MRI

Question 4

Vestibular schwannoma radiologic findings

Answer 4

CT: used to determine bony remodeling, may be negative for small lesions. Larger lesions may demonstrate expansion of the IAC, blunting of the porous acousticus
MRI: Hypointense mass on T1 (lower signal intensity than normal brain parenchyma), iso or heterogeneously hyperintense on T2, moderate to avid enhancement on postcontrast images, no restriction on diffusion weighted images

Question 5

Difference between T1 and T2 weighted images

Answer 5

T1: grey matter appears darker than the white matter . Inflammation appears dark, water appears dark, blood appears bright, fat appears bright
T2: grey matter appears lighter than the white matter, fat appears bright, water appears bright, inflammation appears bright

Question 6

FLAIR

Answer 6

Fluid attenuated sequences. T2 weighted. Fluid will not appear bright

Question 7

Meningioma radiologic findings

Answer 7

CT: 2/3 are hyperintense relative to the brain, homogenous and occasionally calcified, enhance with contrast.

MRI: Variable intensity on T2, isointense or slightly hypointense on T1, surface voids may be present, dural tail present

Question 8

Glomus jugulare radiologic findings

Answer 8

CT: soft tissue mass with avid enhancement, associated with bony destruction
MRI: salt and pepper appearance on both T1 and T2. Hypointense on T1 with focal areas of hyperintense signal which may represent hemorrhage. Hyperintense on T2 with focal areas of signal drop off. Avid enhancement on post contrast images.
Will show radiotracer uptake on nuclear scans.

Question 9

Fibrous dysplasia radiologic findings

Answer 9

Lesions are developmental and not neoplastic. Represent immature bone. Can be monostotic or polyostotic form (polyostotic associated with McCune Albright syndrome)

CT: Classic ground glass appearance with associated bone expansion but not bony erosion or destruction. Larger lesions cause neural foraminal narrowing because of mass effect

MRI: Hypointense on T1 and T2. Moderate to avid enhancement on postcontrast images.

Question 10

Persistent stapedial artery

Answer 10

Often not seen on imaging but if seen

CT: may demonstrate a soft tissue mass at the level of the stapes, expansion of the tympanic facial canal and Y configuration of the geniculate fossa, representing the facial hiatus for the GSPN and the channel for the persistent stapedial artery which becomes the middle meningeal artery. Foramen spinosum is absent.

Question 11

Endolymphatic sac tumors on MRI

Answer 11

Hyperintense on T1 and T2