颅内血管周细胞瘤的MRI表现

MR Imaging Diagnosis and Pathologic Analysis in Intracranial Hemangiopericytoma

目的 探讨颅内血管周细胞瘤（HPC）的MRI表现特征。方法 回顾性分析经病理学证实的HPC患者14例术前MRI平扫及增强检查资料,男10例,女4例,年龄33~69岁,平均（48.2±3.6）岁。观察肿瘤发生的部位、形状、MRI信号表现及强度。结果 肿瘤发生于蝶骨嵴5例,大脑镰3例,颞叶4例,枕叶2例,直径3.4~6.1cm。肿瘤呈浅分叶状或不规则形,境界较清。MRI平扫T1WI呈等及略低信号,T2WI呈等及略高信号,DWI呈低信号,其内有血管流空及多发灶性囊变坏死,增强后肿瘤呈明显强化,2例肿瘤显示脑膜尾征,8例肿瘤周围脑实质轻度水肿,3例肿瘤周围脑实质中度水肿,1例瘤旁颅骨小片状骨质破坏。结论 中青年患者,颅内以窄基底或宽基底与脑膜相连的浅分叶状肿块,其内有散在分布灶性坏死或微出血,T1WI呈等及略低信号,T2WI呈等或稍高信号,DWI显示为稍低信号或混杂低信号,增强扫描明显强化且其内或边缘有血管流空,应高度怀疑HPC。HPC的MRI表现虽有一定特点,但确诊仍依靠病理及免疫组织化学检查。

Objective To investigate the MR findings and pathologic bases of intracranial hemangiopericytoma （HPC）. Methods All 14 cases with HPC were proved by histopathology. All 14 cases were undergone preoperative MRI plain scan and phases enhancement scan, and MRI characteristics of HPC in 14 cases （ 10 cases of male, 4 cases of female, aged from 33 to 69 years old, average 48.2 ＋ 3.6） were analyzed retrospectively. Results Out of 14 cases of tumor with 3.4 cm to 6.1 cm in diameter, 5 cases occurred in sphenoid ridge, 3 cases occurred in falx, 4 cases in temporal lobe and 2 cases in occipital lobe. The findings of tumors were mainly lobulated and irregular in shape. The lesions showed isointensity on Tj WI and T2WI. The lesions showed hypointensity on diffusion weighted image. The lesions with no signal blood vessels and multiple necrotic cysts demonstrated markedly inhomogeneous enhancement after injection of Gd - DTPA. Dural tail sign was present in 2 cases. The lesions showed parenchymal mild edema in 8 cases, parenchymal moderate edema in 3 cases and lamellar bone destruction in 1 case. Conclusion Among young and middle aged patients, the intracranial tumor showed with narrow basal or wide base and meningeal shallow lobulated mass, which has spread in the distribution of focal necrosis or hemorrhage, isointense or slight hypointense on T1WI, isointense or slight hyperintense on T2WI, slight hypointense or mixed signal on DWI, and marked enhancement, vascular flow signal by enhanced scan, should be highly suspected of HPC. Although MRI findings of HPC has certain characteristics, but still depends on pathological diagnosis and immunohistochemical examination for diagnosis.