探讨幕下脉络丛乳头状瘤（CPP）的MR表现及临床病理特征。

回顾性分析解放军联勤保障部队第九二六医院放射科与许昌市立医院放射科自2010年1月至2019年1月经手术病理证实为幕下CPP的19例患者的MR表现及临床病理特征，主要包括病灶位置、形态、大小、信号及病理。

17例（89.5%）瘤体主要位于四脑室，2例（10.5%）瘤体主要位于右侧孔区，瘤体可沿枕骨大孔或侧孔铸形生长，信号相对均匀，仔细观察其内可见颗粒状混杂信号，与病理结构相符，DWI呈低或稍低信号，增强明显强化，瘤体内可见桑椹状、细小颗粒状不均匀强化区。14例（73.7%）合并钙化，5例（26.3%）合并小囊变，16例（84.2%）合并脑积水。

幕下CPP的MR表现有一定特征，充分认识其MR表现，可提高术前误诊率。

To investigate the MR findings and clinicopathological features of infratentorial choroid plexus papilloma (CPP).

The MR manifestations and clinicopathological features of 19 patients with subtentorial CPP confirmed by operation and pathology from January 2010 to January 2019 in the Department of Radiology, 926 Hospital of PLA Joint Logistics Support Force and the Department of Radiology, Xuchang Municipal Hospital were analyzed retrospectively, mainly including the location, shape, size, signal and pathology of the lesion.

Seventeen cases (89.5%) of the tumors were mainly located in the fourth ventricle, 2 cases (10.5%) of the tumor were mainly located in the right luschka, the tumor can be cast along the large or lateral hole of the occipital bone. The signal was relatively uniform, and the granular mixed signal can be observed carefully, which was consistent with the pathological structure. DWI showed low or slightly low signal intensity and enhanced obviously. Mulberry-like and fine granular inhomogeneous enhancement areas could be seen in the tumors. Fourteen patients (73.7%) had calcification, 5 patients (26.3%) had small cystic changes, and 16 patients (84.2%) had hydrocephalus.

The MR performance of infratentorial CPP has certain characteristics, and a full understanding of its MR performance can improve the rate of preoperative misdiagnosis.