鞍区生殖细胞瘤的MRI特征分析

Analysis of MRI characteristics of saddle area germinoma

目的分析鞍区生殖细胞瘤的磁共振成像(MRI)表现特征及临床特点,以提高在临床工作中对本病的认识。方法回顾性分析12例鞍区生殖细胞瘤患者的临床和MRI资料,均行MRI的T1WI、T2WI、DWI、增强序列扫描。结果鞍区生殖细胞瘤呈较均质T1WI等或稍低信号、T2WI等或稍高信号,DWI为高信号,增强呈较均匀强化;鞍区生殖细胞瘤均有垂体柄增粗达15 mm以上和垂体后叶正常短T1高信号消失;根据肿瘤发生的部位及侵犯范围不同分为3类:垂体柄增粗病灶、V形或Y形病灶、不规则形肿块,所占比例分别为2/12(16.7%)、6/12(50.0%)、4/12(33.3%);1例鞍区生殖细胞瘤沿穹窿播散;12例患者主要临床症状为中枢性尿崩症。结论 MRI软组织分辨率高,并能多方位成像,可以清晰显示肿瘤形态、信号特点、累及范围及播散灶,再结合患者的性别、年龄及临床表现,有助于颅内生殖细胞瘤诊断。

Objective To analyze magnetic resonance imaging（MRI） manifestations and clinical characteristics of saddle area germinoma, in order to improve understanding of the disease in clinical work. Methods Clinical and MRI data of 12 saddle area germinoma patients were retrospectively analyzed. The patients all received MRI scanning for T1 WI, T2 WI, DWI, and enhanced sequence scan. Results Lesions of saddle area germinoma were shown by T1 WI as isointense or slightly hypointense, as isointense or slightly hyperintense by T2 WI, and hyperintense by DWI. The enhancements were all shown as homogeneous. Thickness of pituitary stalk over 15 mm and disappearance of normal T1 hyperintense in posterior pituitary were observed in all saddle area germinoma cases. These cases could be divided by onset location and extent into three types, as thickening pituitary stalk, V or Y shape, and irregular mass. Their proportion were respectively 2/12（16.7%）, 6/12（50.0%）, 4/12（33.3%）. There were 1 case with spread saddle area germinoma in fornix and 12 cases with main clinical symptom as central diabetes insipidus. Conclusion High resolution of soft tissue and multi-dimensional imaging of MRI can clearly show tumor morphology, signal features, involved area and spread lesion. MRI combined with patients＇ gender, age and clinical manifestations is helpful for diagnosis of intracranial germinoma.