NMR imaging

Three epidermoid and two dermoid tumours, pathologically proven, were examined by NMR and CT scans. Although most brain tumours have a low signal with a long T1, a dermoid cyst and one of the two components of the other dermoid tumour had a high signal and therefore a short T1. All three epidermoid tumours had a low signal and a long T1. Because of the high level contrast between some of the tumours and cerebrospinal fluid, NMR is helpful to detect the lesion. Neither of the liquid fluid levels in the tumour cysts or floating fat in the subarachnoid space was recognized in one patients, but the fine leakage of the content from the epidermoid cyst into the lateral ventricle was detected on a saturation recovery 1000 image in one case. (author)