松果体实质细胞肿瘤的MRI表现

MR imaging characteristrics of pineal parenchymal tumors

目的:探讨松果体实质细胞肿瘤的MRI表现。方法:本院6例经手术病理证实的松果体实质细胞肿瘤患者,术前均行MRI检查,1例行CT检查。其中松果体细胞瘤(PC)4例,中分化松果体实质细胞肿瘤(PPTID)1例,松果体母细胞瘤(PB)1例。结果:4例PC平均直径2.4cm,PPTID、PB最大径分别为3.1和2.1cm。5例肿瘤呈类圆形或浅分叶,1例呈不规则形;4例肿瘤边界清晰,2例边界不清。MRI平扫除1例明显出血呈混杂信号外,其它5例以实性稍长T1稍长T2信号为主。5例肿瘤DWI呈稍高或高信号,1例呈等低混杂信号。增强扫描示1例肿瘤呈环形强化,5例略不均匀强化,其中轻度-中度强化3例、明显强化3例。5例出现不同程度梗阻性脑积水。结论:松果体实质细胞肿瘤的MRI表现具有边界相对清楚、实性为主、略不均匀强化以及DWI上呈稍高或高信号的特点。

Objective：To assess the MRI features of pineal parenchymal tumors （PPTs）,so as to improve capability of diagnosis for PPTs. Methods：Six patients with PPTs proved surgically and pathologically underwent on MRI examination and one case was done CT examination,including pineocytoma （PC, n： 4）, pineal parenchymal tumor of intermediate differ- entiation （PPTID, n= 1） and pineoblastoma （PB, n： 1）. Results： The average size of PC, PPTID and PB was 2.4cm, 3.1 cm and 2. 1cm, respectively. Five tumors showed oval or shallow lobulated shape. 4 tumors had clear border. On plain scanning, 1 case had mixed signal due to hemorrhage. 5 cases were dominated by solid slight hypointensity on T1WI and slight hyper- intensity on T2WI. 5 tumors showed slight hyperintensity or hyperintensity on DWI. After contrast administration, 1 case had ring-shaped enhancement and 5 slight heterogeneous enhancement,in which 3 showed mild to moderate enhancement and 3 was marked enhanced. Five cases had hydrocephalus in various degree. Conclusion： This research demonstrated the PPTs are characterized by a relatively clear boundary,mainly solid entity and slight inhomogeneous enhancement on MRI and slight hyperintensity or hyperintensity on DWI.