What differentiates between an arachnoid cyst and epidermoid cyst?
An epidermoid cyst has restricted diffusion whereas an arachnoid cyst has free diffusion
Left cerebellopontine angle mass which is high signal on T2 and low signal on T1 (isointense to CSF) and demonstrates restricted diffusion on DWI. High resolution CISS images show cranial nerves going through the lesion