Central nervous system disorders

II./3.5.: Take home messages

• - Contrast enhancement of extraaxial tumors is usually strong (no blood-brain barrier).

• - Signal of primary brain tumors is usually low on T1 weighted, and high on T2 weighted images.

• - Hypercellular tumors, especially those with a cell content of large nuclei, have low signal on T2 weighted images.

• - Inside the fluids, the Brown motion related diffusion is free, therefore, there is no signal increase on DWI images.

• - Perfusion (tissue devolution) depends on the vascularisation of the tumor.