基底节区生殖细胞瘤的MRI和MRS征象分析

MRI and MRS Features of Germinoma in Basal Ganglia

目的:探讨基底节区生殖细胞瘤的MRI和MRS特征,以提高诊断准确性。方法:回顾性分析经手术病理证实或诊断性放疗临床确诊的8例基底节区生殖细胞瘤的临床及影像学资料。结果:8例基底节区生殖细胞瘤均为男性,年龄11~23岁,平均16.4岁;肿瘤实质部分T1WI呈略低于或接近脑灰质信号,T2WI和FLAIR呈高或稍高信号,DWI呈高信号;肿瘤呈实性团块状1例,肿瘤伴有囊变或呈完全囊性7例(87.5%,7/8),其中囊性伴分隔3例,囊实性4例;瘤周轻度水肿或无水肿7例(87.5%),无明显占位效应4例(50%);增强后病灶可呈环形、分隔状、斑点状、片状、团块状强化,其中1例肿瘤无明显强化;肿瘤伴有不同程度的同侧丘脑、脑干萎缩7例(87.5%,7/8),其中2例同时伴有同侧大脑半球及基底节的萎缩;3例患者同时行MRS检查,均表现为NAA峰降低,Cho峰增高,其中1例出现明显增高的Lip峰。结论:基底节区生殖细胞瘤MRI表现有一定特征性,结合MRS及临床资料,可以提高基底节区生殖细胞瘤的诊断准确率,尤其是对早期阶段的基底节区生殖细胞瘤进行早期诊断、早期治疗而改善患者预后。

Purpose： To investigate the MRI and MRS features of basal ganglia germinoma to improve the diagnostic accuracy of this tumor. Methods： The clinical and imaging data of 8 patients with basal ganglia germinoma proved by pathology or by radiotheraphy results were analyzed retrospectively. Results： All 8 patients with germinoma arising from basal ganglia were male, and their ages were ranged from 11 to 23 years old, and their mean age was 16.4. Tumor parenchyma was shown with iso-intensity or slightly hypo-intensity on T1 weighted images when compared to gray matter, hyper-intensity or slightly hyper-intensity on FLAIR and T2 weighted images, and hyper-intensity on DWI. MRI showed solid lesion in 1 case, cystic degeneration or totally cystic lesion in 7 cases （87.5%, 7/8）, including cystic lesion with separation in 3 cases, solid lesion with cystic portion in 4 cases. MRI showed slight edema or without edema around the tumor in 7 cases （87.5%）, without space-occupying effect in 4 cases （50%）. On post contrasted images, ring-like, separation, spotty, patchy or nodular enhancement was showed in 7 cases. But 1 case was not shown with enhancement in the lesion. Different degrees of ipsilateral thalamus and brainstem atrophy were showed in 7 cases （87.5%,7/8）, 2 cases were also with ipsilateral hemisphere and basal ganglia atrophy. Three patients were undergone MR Spectroscopy. Increased Cho peak and decreased NAA peak was seen in all 3 cases, and increased Lip peak was seen in 1 case. Conclusion： The MRI features of germinoma inbasal ganglia have certain characteristics. When combined MRI with MRS and clinical data, the diagnostic accuracy could be improved. In order to improve the prognosis, early diagnosis and treatment for basal ganglia germinoma are necessary, especially for the tumor in early stage.