儿童基底节和丘脑生殖细胞瘤的CT及MR影像诊断

CT and MR imaging of germinomas arising in basal ganglia and thalamus

目的研究基底节及丘脑生殖细胞瘤的ＣＴ、ＭＲ影像表现，并与其他部位生殖细胞瘤的影像表现进行对照，以提高诊断水平。方法回顾性分析了１１例基底节及丘脑生殖细胞瘤ＣＴ、ＭＲ影像资料，并与其他部位８６例生殖细胞瘤进行对照分析。１１例全部为男性，年龄３～１５岁，平均１０．６岁。１１例患儿中９例经ＭＲ检查，其中５例在ＭＲ检查前作了ＣＴ检查；２例仅作了ＣＴ扫描。结果１１例中９例位于基底节，２例位于丘脑；６例表现为圆形或椭圆形，５例形态不规则，边缘呈分叶状；５例肿瘤内可见囊变、坏死灶。９例经ＭＲ检查者，Ｔ１加权像４例见肿瘤内有斑块样出血灶。静脉注入对比剂后，９例表现为斑块样或斑片样增强，１例为环形增强，１例为环形分隔样增强。４例见肿瘤向对侧基底节扩散。５例基底节生殖细胞瘤可见同侧大脑皮层萎缩征象。结论基底节及丘脑生殖细胞瘤的发病性别、好发部位、ＣＴ及ＭＲ影像表现具有一定特点，在多数情况下可以作出术前诊断。

Objective To evaluate the role of CT and MR imaging in diagnosing germinomas arising in the basal ganglia and thalamus. Methods MR imaging of 11 boys (ranging in age from 3 15 years with a median of 10.7 years) with germinomas arising from the basal ganglia and thalamus was reviewed retrospectively and the imaging findings were compared with the features of 86 germinomas in other regions. The tumors located at basal ganglia in 9 and at thalamus in 2. All diagnosis was proved operatively and pathologyically. Five cases were studied using both CT and MR, 4 were examined with MR and 2 with CT only. Results In this series of 11 tumors, 9 were located in the basal ganglia and 2 in the thalamus. The shape of six tumors was global and 5 was lobulated. The cystic components or necrosis were intratumoral in 5 patients and hemorrhage in 4. Patchy enhancement was found in 9 patients and ring enhancing lesions in 2. Tumor spread oppositely in 4 patients. Five patients demonstrated cortical atrophy ipsilaterally. Conclusion The germinomas arising from the basal ganglia and thalamus have sex, location and imaging characteristics. Therefore, it is possible to make preoperative diagnosis using CT or MR.