[Contrast medium enhanced MRT of tumors of the posterior fossa in children and adolescents].

The results of contrast-enhanced MR in 24 children and adolescents with tumours of the posterior cranial fossa are presented. During initial diagnosis, the majority of tumours showed intensive enhancement with improved demarcation from neighbouring structures. The solid component of a cystic tumour, even when small and not visible on the original scan, could be demonstrated in all cases by means of gadolinium-DTPA. Post-operatively, T2-weighted scans regularly showed areas of high signal strength at the margin of the resection; in the absence of a mass or demonstrable progression, the significance of this is uncertain. In these cases gadolinium-DTPA, because of the function of the blood-brain barrier, greatly increases accuracy in demonstrating residual or recurrent tumours.