大脑半球的蛛网膜下腔出血或中线硬膜下血肿。在ＣＴ上常常易与正常大脑镰混淆。有关大脑镰的正常ＣＴ表现，文献报道较少。本文通过对各个正常年龄组大镰及相关结构ＣＴ表现的分析．进一步提高认识。材料与方法收集ＣＴ平扫显示正常的２００例头颅图像．分为８个年龄组，凡有 Subarachnoid hemorrhage in the hemisphere or midline subdural hematoma. Often confused with normal falx on the CT. The normal manifestations of falx sickle, reported in the literature less. This article through the normal age group sickle and related structures CT performance analysis. To further raise awareness. Materials and Methods 200 cases of normal skull CT images were collected. Divided into 8 age groups, where there is