TECTAL PLATE GLIOMAS .2. CT SCANS AND MR-IMAGING OF TECTAL GLIOMAS

CT scans and MR images were analized in 12 patients with histologicall y proved tectal plate gliomas. In an attempt to identify the nature of these lesions, their radiological characteristics were correlated wit h the histological results. In four of our patients CT scan failed to show the tumour. MR imaging demonstrated the tectal distorsion in all cases. Contrast enhancement, calcification, cystic portions, exophytic nature were observed in both high and low-grade gliomas. We conclude that in the case of intrinsic tectal tumours, the most probable diagno sis is that of low-grade astrocytoma while in the case of exophytic te ctal tumours, the differential diagnosis from pineal region tumour is required and a histological verification is necessary.