Parameters of infiltration in posterior fossa tumours of childhood using a high resolution CT scanner.

The computed tomographic changes in 23 posterior fossa tumours of childhood scanned on a GE 8800 scanner have been compared with the detailed operative reports in order to evaluate morphological features indicative of infiltration. The study indicated that the cyst wall of a cystic astrocytoma was always easily enucleated and was free from infiltration and that a sharp enhancing edge of a medulloblastoma or centrally necrotic astrocytoma was usually also not the site of infiltration. Other features however were found to be unreliable.