Brain tumors MRI terminology

1-It is essential to know that for brain tumors diagnosis, you should give contrast.

2-Some tumors are composed of very large amounts of cells, these will give intermediate signal in both T1,T2 imaging, while the tumors containing more water, will give more hypo intense signal in T1 and more hyper intense signal in T2, so it is essential to give contrast and watch the effect of this injection on the tumor.

3- When you gives contrast, you can have the following responses according to the type of the tumor:
-No enhancement.
-There is enhancement by one of the following types of enhancement
*Homogenous enhancement.
*Heterogenous enhancement.
*Or ring enhancement.

4-The report of the brain tumors should include the following:
 Mnemonic 4 S  4 E
-Site.
-Size.
-Shape.
-Signal intensity.

-Edge.
-Enhancement.
-Edema.
-Effect which is mass effect.

-Then mention the normal findings.

5-Mass effect:

Radiological signs of mass effect

-Effacement of the cortical sulci (grade 1 ).
-Compression of the epsilateral ventricle (grade 2 ).
-Shift of the mid line structures to the contra lateral side (grade 3). 

6-Brain edema:

-Two types (vasogenic edema like fingers or tree) and (cytotoxic edema like a circle surrounding the lesion).

-Vasogenic edema has three grades which are

*Grade 1 : when the edema surrounding the tumor is less than 2 cm in thickness( as in low grade tumors ).
*Grade 2 : When the edema is more than 2 cm but less than half the cerebral hemisphere.
 *Grade 3 : More than half of the cerebral hemisphere(as in aggressive tumors).