Diffusion-weighted MRI postoperative assessment of an epidermoid tumour inthe cerebellopontine angle

Cerebellopontine angle epidermoid tumour generally has a typical appearance with conventional MRI sequences. The lesion is irregular in shape and give s slightly higher signal than cerebrospinal fluid on T1- and T2-weighted im ages, with a characteristic marbled inner pattern on T1-weighted images. Di ffusion-weighted imaging (DWI) can be useful for the diagnosis of an atypic al epidermoid tumour. Our case report illustrates the usefulness of DWI for postoperative assessment of residual foci of tumour. The specific appearan ce of an epidermoid tumour is illustrated, with emphasis on apparent diffus ion coefficient (ADC) measurements.