儿童幕上间变型室管膜瘤的CT及MRI影像学研究

CT and MRI features of supratentorial anaplastic ependymomas in children

目的:探讨分析儿童幕上间变型室管膜瘤的CT及MRI特征。方法:回顾性分析经手术病理证实的12例幕上间变型室管膜瘤患儿的临床、CT及MRI资料,同时测量分析肿瘤实质的平均表观扩散系数(mean apparent diffusion coefficient,ADCmean)、最小ADC(minimum ADC,ADCmin)及相对ADC(relative ADC,r ADC)。所有患者术前均行常规MRI及扩散加权成像(diffusion weighted imaging,DWI)检查,10例在MRI检查前行CT平扫。结果:11例肿瘤位于脑实质,1例位于三脑室,脑实质内肿瘤体积较大。CT扫描中,5例肿瘤实质为等密度,5例呈稍高密度。8例有钙化,其中6例呈砂粒样。12例肿瘤均为囊实性,其中10例为大囊变。8例肿瘤囊性成分邻近同侧侧脑室,其中6例实性成分位于脑皮层侧。3例肿瘤无瘤周水肿,7例表现为轻度,2例呈中度。肿瘤实性成分在T1WI上为等低信号,T2WI上为等高信号。增强后,11例肿瘤呈花环样强化,1例呈不均匀伴结节样强化。11例在DWI上为稍高信号,1例为等信号。肿瘤ADCmean为(0.757±0.149)×10-3 mm2/s,ADCmin为(0.601±0.114)×10-3 mm2/s,r ADC为(0.867±0.185)×10-3 mm2/s。结论:儿童幕上间变型室管膜瘤的CT及MRI影像学表现具有一定特征性,有助于术前诊断。

Objective To analyze the CT and MRI features of pediatric supratentorial anaplastic ependymomas.Methods： Clinical information and image findings of 12 children with pathology-confirmed supratentorial anaplasticependymomas were retrospectively reviewed. The mean apparent diffusion coefficient （ADCmean）, minimum ADC（ADCmin） and tumor/nomal brain relative ADC （rADC） of solid component of tumors were measured. All patientsunderwent MRI scans before operation, 10 patients also underwent CT scans before MRI scans. Results： The tumorwas located at the third ventricle in one case, at the parenchyma in 11 cases. On CT plain scan, the solid componentsin 5 cases showed isodensity, and hyperdensity in 5 cases. Eight cases had calcification and 6 cases showed speckledcalcification. All tumors were cystic and solid, and 10 showed huge cystic degeneration. Eight tumors appeared as cysticcomponent closed to the lateral ventricle and 6 tumor’s solid component was located at the cortex. Three cases had noperitumoral edema, 7 cases appeared mild peritumoral edema, and 2 cases presented moderate peritumoral edema. Thesolid component of the tumors showed iso-hypointensity on T1WI, and iso-hyperintensity on T2WI. All tumors showedobvious enhancement, 11 with ring-like enhancement, and 1 with heterogenous enhancement accompanied with nodularenhancement. Eleven cases showed slightly hyperintense on diffusion weighted imaging （DWI）, 1 case presentedisointense. The ADCmean value was （0.757±0.149）×10^-3 mm2/s, ADCmin value was （0.601±0.114）×10^-3 mm2/s,and rADC value was （0.867±0.185）×10^-3 mm2/s. Conclusion： The CT and MRI manifestations of supratentorialanaplastic ependymoma in children are characteristic, which must be helpful in the diagnosis.