颅内血管外皮瘤MRI诊断以及临床意义

MRI Diagnosis of Intracranial Hemangiopericytoma

目的分析颅内血管外皮瘤(HPC)磁共振影像特征并与病理学对照,提高对HPC的认识和术前诊断准确性。方法回顾性分析经手术病理证实的26例颅内HPC患者资料,其中男12例,女14例,平均年龄(46.8±13.8)岁,术前24例行MR平扫及增强扫描。19例行水抑制T2WI,20例行扩散加权成像,8例行MR波谱成像,6例行灌注成像。3例行MRA,2例行MRV。分析其在不同序列上的影像特征并和病理对照。结果 26例HPC好发部位依次为旁矢状窦面、蝶骨翼区、天幕周、鞍区及大脑凸面。92.3%(24/26例)呈窄基底与脑膜相连。易侵犯硬膜及静脉窦。HPC实质呈T1WI等低、T2WI等高信号,强化不均。瘤内出血、囊变多见。部分囊变区强化明显,亦可见壁强化。肿瘤实质在ADC上呈等高信号,灌注成像上示肿瘤灌注高于皮质区。MR波谱成像上75%(6/8例)出现Cho增高,100%(8/8例)NAA及Cr峰降低,25%(2/8例)在3.56 ppm处出现一个较高的肌醇峰。33%(1/3例)可显示来自于左大脑前动脉的供血动脉。2例行MRV均可显示瘤周迂曲血管,以及静脉窦侵犯范围。结论 HPC少见,但在磁共振成像上有一定的特异性,rADC值、MR波谱成像、磁共振灌注成像有助于诊断,术前MRA及MRV对其诊断有一定指导意义。

Objective To analyze and compare imaging features with pathological findings of intracranial hemangioperi- cytoma （ HPC）, and to improve awareness of the HPC and preoperative diagnostic accuracy. Methods Routine MRI scan were performed in all 26 cases, FLAIR T2WI were obtained in 19 cases, and DWI in 20 cases, MR spectroscopy in 8 ca- ses, perfusion MRI in 6 cases. MRA was obtained in 3 cases and MRV in 2 cases. All results were compared with patholo- gial results. Results In 26 cases, the most frequent anatomic tumor sites were sagittal sinus surface, sphenoid wing area, canopy weeks, the saddle area and brain convexity. 92.3 % （24/26） of tumors connected meningeal on the narrow basal. Tumors easily invade the venous sinus. On MRI, the lesions showed mixed iso or low signal on Tl WI, mixed iso or high signal on T2 WI, heterogeneous enhancement was seen in all 26 cases. Necrosis and cyst were common, part of cystic area showed marked enhancement, while cystic wall was enhanced occasionally. On DWI, tumor parenchyma was high signal. Tumor showed a significantly higher perfusion level than the cortex on PWI. On MRS, 75% （6/8） of cases were seen CHO increased to 100% （8/8） NAA and Cr peak decrease, 25% （2/8）of cases were seen a higher myoinositol peak at the 3.56 ppm. Conclusion Intracranial hemangiopericytoma is rare, but it has some features in magnetic resonance imaging. rADC, MRS, PWI are helpful in diagnosis, preoperative MRA and MRV have some clinic significance.