J Korean Radiol Soc.  1994 Aug;31(2):217-222.

CT and MR Findings of Supratentorial Pilocytic Astrocytoma

• Kim DI
• Kim EK
• Chung TS
• Suh JH

Abstract

PURPOSE
Pilocytic astrocytoma is a benign tumor predominantly arising from cerebellum in pediatric age. But it occasionally arises in supratentorium. We describe radiologic findings of supratentorial pilocytic astrocytoma.
MATERIALS AND METHODS
Eleven CT and 7 MR examinations in 11 patients were retrospectively reviewed with attention to location, CT density, MR signal intensity, and degree and pattern of contrast enhancement on CT and MR.
RESULTS
The tumors were located around the third ventricle (hypothalamus in three cases, optic chiasm in three cases) and in cerebral hemisphere (temporal lobe in three cases, frontal lobe in one case, thalamus in one case). On CT, the tumors were all sharply demarcated and rarely associated with edema. The tumors showed moderate to strong contrast enhancement. Necrosis appeared frequently in tumors around the third ventricle in contrast to frequent cyst formation in hemispheric masses. On MR, the tumors appeared hypo- or isointense on T1- weighted images and hyperintense on T2- weighted images. After administration of contrast agent, the tumors showed intense enhancement more than that of CT.
CONCLUSION
The typical location and radiologic findings described above are helpful in the diagnosis of the supratentorial pilocytic astrocytoma.

MeSH Terms

Astrocytoma*
Cerebellum
Cerebrum
Diagnosis
Edema
Frontal Lobe
Humans
Necrosis
Optic Chiasm
Retrospective Studies
Thalamus
Third Ventricle