颅内和体部血管外皮细胞瘤:MR平扫和动态增强的诊断价值

The Plain and Dynamic MR Enhanced imaging in the Diagnosis of Intracranial and Bodily hemangiopericytoma

目的分析颅内和体部血管外皮细胞瘤的MR特征，探讨MR对其的诊断价值。资料与方法经手术病理证实的血管外皮细胞瘤9例，术前均经MR检查。MR检查序列包括SE T1WI、FSE T2WI、FSE T2WI脂肪抑制和梯度回复回波（GRE），其中6例行SE T1WI或GRE动态增强扫描。分别确定病变形态、信号特征和强化程度，并与手术病理进行对照。结果 9例中，位于颅内3例，四肢4例，腹膜后1例，腹股沟1例。病灶多呈不规则分叶状软组织肿块，直径4．8～13．5cm，平均6．7cm，其中〈5cm1例，5～10cm7例，〉10cm1例。9例病灶内可见坏死，6例可见蚯蚓状和结节状血管流空信号。SE T1WI肿瘤实质成分呈低、等或略高信号，所有病例T2WI呈等或略高信号。6例动态增强扫描病例中，动脉期显著强化5例，中等程度强化1例；门脉期均显著强化，强化程度与邻近大血管相仿。颅内、外血管外皮细胞瘤的MR表现无明显区别。结论血管外皮细胞瘤呈不规则分叶状软组织肿块，瘤内常见血管流空和坏死，T2WI呈略高信号，动态增强扫描呈进行性延迟强化，强化显著。

Objective To explore the dynamic MR findings of intracranial and bodily hemangiopericytoma, and evaluate its clinical value. Materials and methods 9 cases with intracranial and bodily hemangiopericytoma confirmed by surgical pathology received MR plain scanning and multi phase dynamic enhancement scanning before operation, the MR data including shape of lesion and signal intensity were reviewed and analyzed retrospectively in comparison with surgical and pathological results. Results 3 of 9 lesions were located in intracranium, 4 in limb, 1 in retroperitoneum and 1 in inguen respectively. The tumor tended to be irregular multilobulated in shape. The diameter of the tumors was 4.8 cm - 13.5 cm （ with a mean diameter of 6.7 cm） with 1 case less than 5.0 cm, 7 cases with 5.0 cm - 10.0 cm and 1 case more than 10 cm. The tumor presented slightly hypo to isointensity signal on SE T1 weighted imaging, and iso to slightly hyperintensity on FSE T2 weighted imaging with necrosis in 9 cases and multiple signal voids of vessel in 6 cases. 6 cases underwent dynamic enhancement scanning presented obvious enhancement in the artery phase and persistent enhancement in the portal vessel phase similar to enhancement of adjacent large vessel. The MR appearance of intracranial hemangiopericytoma was similar to that of bodily hemangiopericytoma. Conclusion The intracranial and bodily hemangiopericytomas have irregular multilobulated in shape and present iso to slightly hyperintensity signal on FSE T2 weighted imaging with necrosis and multiple signal voids of vessel, and present obvious enhancement in two phases contrast scans.