 |
Axial T2 |
 |
Axial Flair |
 |
Axial T1 |
 |
Axial T1 post gad |
 |
DWI |
Most important differential:
Epidermoid Cyst (sebaceous cyst).
Differentiating points:
1. Arachnoid cyst shows no restriction on DWI, Epidermoids highly restrict!
2. Arachnoid cysts lose signal on FLAIR (iso to CSF), while epidermoids will be hyper to CSF on FLAIR.