颅内血管周细胞瘤的MRI诊断

MRI diagnosis of intracranial hemangiopericytoma

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。方法分析6例经手术病理证实的颅内H PC的临床和影像资料，6例均行M RI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T1 WI、T2 WI信号均匀，增强明显均匀强化，脑内病灶T1 WI呈稍高信号、T2 WI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 H PC少见，M RI形态及增强表现较有特征性，总结M RI表现，可提高术前诊断准确性。

Objective Hemangiopericytoma （HPC） is rare intracranial tumor .The purpose of this work was to analyze the MRI features of intracranial HPC so as to 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 ,with an 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 3 cm with clear boundary .Lesions outside the brain parenchyma were uniform on T1WI ,T2WI and enhanced homogeneously .Intraparenchymal lesions were shown slightly high signal on T1 WI and slightly high ,mixed signal on T2 WI .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 characteristics .Therefore ,sum‐marizing the M RI features can improve the preoperative diagnostic accuracy .