颅内软骨瘤的CT与MRI诊断

CT and MRI Diagnosis of Intracranial Chondroma

目的分析颅内软骨瘤的CT、MRI表现特点。方法对经手术病理证实的4例颅内软骨瘤进行回顾性分析,3例行颅脑CT平扫,1例同时行颅脑CT增强扫描,4例均行颅脑MR平扫及增强扫描。结果 4例颅内软骨瘤中,位于颅底3例(前颅窝底1例,蝶鞍1例,左侧中颅窝底1例),大脑镰区1例。CT平扫示3例肿瘤均边缘清楚,内均见明显钙化灶,其中2例肿瘤的未钙化部分呈不均匀的稍高密度,1例呈"石榴籽"样低密度;CT增强扫描肿瘤呈不均匀强化;M R I平扫肿瘤均表现为混杂信号,其中钙化部分呈长T1短T2信号,未钙化部分呈不均匀的长T1长T2信号,其中1例肿瘤呈"石榴籽"样明显长T1长T2信号;MRI增强扫描肿瘤均呈不均匀强化。结论颅内软骨瘤好发于颅底、大脑镰区,密度/信号欠均匀,内可见到明显的钙化,周围无脑水肿,增强扫描呈不均匀强化。大多数情况下CT、MRI诊断较困难,病理仍是主要的确诊手段。

Objective To analyse the MRI features of intracranial chondroma. Methods CT and MR images of 4 cases with intracranial chondroma confirmed by surgery and pathology were analyzed retrospectively. Three cases were given CT plain exams and one of them post-contrast CT exam at the same time.Four cases were given pre- and post-contrast MR exams. Result Among all the 4cases, 3 cases were located at the skull base（ 1 case at front skull base, l case at sella turcica and 1 case at left-front skull base） and 1 case at the region of falx cerebri. CT scans showed obvious calcification and clear border of the tumors in the 3 cases. Among them, 2 cases showed slightly inhomogeneous htper-density and 1 showed ＂seeds of pomegranate＂ htpo-density. After adiministration of contrast medium, the tu- mors demonstrated hyperdense with inhomogeneous enhancement. MRI images of all the 4 cases showed mixed signals. The calcified element of the tumor showed hypointense signal intensity on T I and T2-weighted images and the uncalcified element showed inhomo- geneous hypointense signal intensity on TI and hyperintense signal intensity T2-weighted images. After adiministration of contrast medium, the tumors demonstrated hyperdense with inhomogeneous enhancement. Conclusion Intracranial chondroma frequently located at the skull base and the region of falx cerebri, with iuhomogeneous density/signals and obvious calcification,wihtout peritumoral edema. The tumors demonstrated hyperdense with inhomogeneous enhancement after adiministration of contrast medium, ratentorial cerebral,usually located at the trigone of lateral ventricle,most appearing solide with slighted peritumoral edema. It is difficult for CT or MRI exams to get accurate diagnosis at most times and it still depends on pathology.