15. Tumors Of Brain And Meninges

Question 1

Modalities - MRI

Answer 1

T1/T1 before/after CM

DWI

MRS: NAA + Alanine

Malignancy: high malignancy (low NAA/Creatine + high Choline)

Question 2

Modalities - CT:

Answer 2

Screening method

Important: do CM

Question 3

Modalities - DSA:

Answer 3

Hypervascularized tumors —> embolization

Question 4

Goals of imaging:

Answer 4

Detection
Differential diagnosis
Grading
Pre-operative set-up
Follow-up: relapsing?

Question 5

Primary vs Secondary tumors:

Answer 5

Primary (rare): glioma, meningioma, pituitary adenoma

Secondary (more common): metastases from lung/breast/melanoma/colorectal/urogenital

Question 6

Glioblastoma (multiforme):

Answer 6

Description: most agressive primary brain tumor, diffusively invasive, «mass effect»

CT:
Non-contrast: heterogenous, hypodense, irregular borders
Contrast: hyperdense borders, hypodense center, central necrosis, surrounding edema

MRI:
T1 contrast: hyperintense borders (capsular hypervascular area), hypodense center
T2: same

Question 7

Meningioma (most common):

Answer 7

Description: slow growing from meninges (dura mater)

Signs:
Angiography: «mother-in-law-sign» enhancement in very early arterial phase + after venous phase
«Dural tail sign» thickening and enhancement of of the dura

Imaging:
MRI non-contrast: isointense (to grey matter in t1/t2)
MRI contrast: hyperintense, homogenous

Therapy:
DSA: pre-operative embolization

Question 8

Brain metastasis:

Answer 8

Description: secondary tumors

Imaging:
CT: hypodense, multiple lesions, at grey/white matter junction
MRI: multiple lesions, surrounding edema, ring enhancement

Question 9

Pituitary adenoma:

Answer 9

Description: slow growing from adenohypophysis

Imaging:
MRI t1 with contrast: microadenoma is hypointense, macroadenoma is hyperintense