Neuro

Question 1

Secondary features of intra and extra-axial tumors

Answer 1

Shape (margination)

Internal architecture -> solid, hemorrhagic, calcified, fatty, cystic

Diffusivity

Enhancement

Question 2

Sellar meningioma vs. pituitary adenoma

Answer 2

Mengiomas may encase and narrow vessels. Pituitary adenomas usually do not narrow the cavernous cartoid a.

Question 3

Hemangiopericytoma origin

Answer 3

Derived from smooth muscle pericyte cells of Zimmerman around the capillaries of the meninges

Question 4

Extra-axial melanocytic lesions?

Answer 4

Diffuse melanocytosis

Melanocytoma

Neurocutaneous melanosis

Malignant melanoma

Question 5

Schwannoma MRI appearance

Answer 5

Isointense to slightly hypointense to white matter on all sequences

Enhancement nearly always evident and homogenous in 70% of cases

Peritumoral edema in 1/3 of cases, typically larger schwannomas

Question 6

Most common nerve involved in intracranial schwannomas?

Answer 6

Inferior vestibular nerve. Althought oscillates between the superior and inferior vestibular nn. frequently.

After CN VIII –> CN VII –> CN V

Question 7

Common post-operative finding in the IAC s/p vestibular schwannoma resection?

Answer 7

Linear gadolinium enhancement. Can be followed expectantly.

Progressive, nodular, or mass like enhancement –> suggest recurrence.