뇌천막 상부에서 발생한 모양세포성 성상세포종의 CT및 MR 소견

Abstract

PURPOSE: Pilocytic astrocytoma is a benign tumor predominantly arising from cerebellum in pediatric age, Butit 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 attentionto 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) andin cerebral hemisphere(temporal lobe in three cases, frontal lobe in one case, thalamus in one case). On CT, thetumors were all sharply demarcated and rarely associated with edema. The tumors showed moderate to strong contrastenhancement. Necrosis appeard frequently in tumors around the third ventricle in contrast to frequent cystformation in hemispheric masses. On MR, the tumors apperared hypo- or isointense on T1-weighted images andhyperintense on T2-weighted images. After administration of contrast agent, the tumors showed intense enhancementmore than that of CT. CONCLUSION: The typical location and radilogic findings described above are helpful in thediagnosis of the supratentorial pilocytic astrocytoma.