血管周细胞瘤

颅内血管周细胞瘤的MRI诊断

王祖飞纪建松杨宏远卢陈英

（浙江丽水市中心医院放射科浙江丽水323000）

【摘要】目的：血管周细胞瘤（Hemangiopericytoma, HPC）较少发生于颅内，分析颅内HPC的MRI表现特征，有利于提高对此种肿瘤的认识。资料与方法：分析6例经手术病理证实的颅内HPC的临床和影像资料，6例均行MRI平扫及增强扫描，其中男性4例，女性2例，年龄32~58岁，平均41岁。结果：本组6例中2例肿瘤发生于桥小脑角区，3例发生于脑实质，1例发生于脑室内，肿瘤体积均大于3cm，边界清，均呈多分叶状，脑外病灶T1WI、T2WI信号均匀，增强明显均匀强化，脑内病灶T1WI呈稍高信号、T2WI呈稍高混杂信号，脑室内病灶接近或稍低于脑白质。注射对比剂后，6例均表现明显强化，内见点片及条状低强化灶，其中2例脑实质肿瘤内见弯曲条状低强化灶。结论颅内HPC 少见，MRI形态及增强表现较有特征性，总结MRI表现，可提高术前诊断准确性。

【关键词】颅内肿瘤血管周细胞瘤磁共振影像诊断

MRI diagnosis of intracranial hemangiopericytoma

Wang Zu-fei, Ji Jian-song, Y ang Hong-yuan, Lu Chen-ying

Department of radiotherapy, The Central Hospital of Lishui, Lishui Zhejiang 323300, China

【Abstract】Objective:Hemangiopericytoma (HPC) is rare intracranial tumor. To analyze the MRI features of intracranial HPC and improve the understanding of this kind of tumor. Methods: The clinical and imaging data of 6 intracranial HPC patients proved by operation and pathology were analyzed retrospectively. All cases(4 males, 2 females, aged 32 to 58 years old, average age of 41) underwent plain and enhanced MRI scan.

Results: In our 6 cases, tumors were located in the cerebellopontine angle(2 cases), brain parenchyma(3 cases), and ventricle(1 case). All of the tumors manifested as lobulated masses larger than 3cm with clear boundary. Lesions outside the brain parenchyma were uniform on T1WI, T2WI and enhanced homogeneously. Intraparenchymal lesions showed slightly high signal on T1WI and slightly high, mixed signal on T2WI. The signal of tumor in ventricle was slightly lower than the cerebral white matter. After injection of contrast agent, all of 6 cases showed obvious enhancement with punctate and striped low density areas, including 2 cases of tumors in the brain parenchyma with crooked striped low density areas. Conclusion: Intracranial HPC is rare. MRI morphology and enhanced manifestations are characteristic. Therefore, summarizing the MRI features can improve the preoperative diagnostic accuracy.

【Keyword】Intracranial tumor; hemanyiopericytoma; magnetic resonance imaging; diagnosis

血管周细胞瘤（HPC）又称血管外皮细胞瘤，并推测肿瘤起源于血管周细胞，是WHO定义的Ⅱ-Ⅲ级肿瘤，易复发及转移。近年来，随着国内外文献报道增多，对本病影像表现有一定认识程度，但术前常常将该病误诊为脑膜瘤，术前正确诊断对肿瘤治疗方案的制定及预后判断很重要。笔者搜集了2003年6月至2013年12月间经过临床手术病理证实的HPC 6例，总结其MR表现，以提高其诊断水平。

1 资料与方法

1.1一般资料

搜集我院2003年6月~2013年12月间经临床手术病理证实的HPC 6例，其中男性4例，女性2例，年龄32～58岁，平均41岁。

临床表现 4例表现为头痛，1例右手活动不灵伴行走不稳，1例表现为左侧面瘫，病程分别为10天到3个月不等。

1.2检查方法

采用Siemens Sympyony 1.5T磁共振设备。常规扫描，采用头线圈，行横断位TIWI、T2WI、T2 FLAIR、DWI扫描。 TIWI扫描参数为

TR=500ms,TE=15ms。T1 FLAIR的扫描参数为：TR=2060ms,TE=25ms，

TI=860ms。T2WI扫描参数为TR = 2400 – 5000 ms,TE=80-120ms。层厚5-8mm，间隔0-2mm。FOV （220-240）×（220-240）mm。6例均行轧双胺（Gd-DTPA）对比增强扫描，行轴位、冠状位、矢状位TIWI扫描。所用参数与平扫T1WI相同。

2 结果

2．1 肿瘤MR表现

6例病灶体积均比较大，直径2.5～5.1cm不等。2例位于左侧桥小脑角区(图1)，其中一例术后1年肿瘤原位复发。3例位于脑实质内（图1~5），位于枕叶或颞枕叶。1例位于脑室内，肿瘤均边缘清楚，呈多分叶状，1例肿瘤压迫脑干，2例侧脑室后角受压变窄；MRI平扫2例脑外肿瘤信号均匀，T1 WI呈等或稍高信号，T2WI呈稍高信号(图6~10)。本组3例脑实质内肿瘤T1WI呈稍高信号， T2WI呈不均稍高信号，脑室内肿瘤信号强度与脑白质相仿。对比增强扫描6例均明显强化，质地不均匀，其中3例内均见斑点状、结节状低或无强化灶（图3~5），1例瘤体内见弯曲条状低信号，2例周围脑实质见明显水肿（图2）。