扩散加权成像在低级别胶质瘤的鉴别诊断价值

Diffusion weighted MR imaging in differentiation of low grade gliomas

目的评价扩散加权成像(DWI)在颅内低级别胶质瘤中的鉴别诊断价值。方法经病理证实的21例低级别胶质瘤,分为Ⅱ级星形细胞瘤(AC,9例)、少突胶质细胞瘤(OD,5例)和少突星形细胞瘤(OA,7例)三组。测量肿瘤实质、瘤周水肿区及对侧正常白质区的ADC、EDC值,并计算相应的rADC及rEDC值。对三组胶质瘤的各组数据进行统计分析。结果OD组肿瘤实质的ADC和rADC值分别为1.12和1.52,OA组分别为1.14和1.48,两组间无明显差异,但均低于AC组的1.93和2.38(P<0.01)。OD组肿瘤实质的EDC和rEDC值分别为0.33和0.70,OA组分别为0.32和0.71,两者间无明显差异,但均高于AC组的0.15和0.34(P<0.01)。瘤周水肿的各参数在三组胶质瘤间无明显统计学差异。结论DWI在区分OD、OA与AC间具有一定的价值,但难以区分OD与OA。

Objective： To assess the value of diffusion weighted imaging （DWI） in the differentiation of intracranial low grade gliomas. Materials and Methods： Twenty- one patients with pathologically proved low grade gliomas were divided into three groups： 9 astrocytomas （AC, grade Ⅱ）, 5 oligodendrogliomas （OD, grade Ⅱ） and 7 oligodendroastrocytomas （OA, grade Ⅱ）. The apparent diffusion coefficient （ADC） and exponent diffusion coefficient （EDC） values in minor solid part, peritumor edema and contralateral white matter of each tumor were measured, relative ADC （rADC） and relative EDC （rEDC） was calculated. Mean values of ADC, rADC, EDC and rEDC were analyzed among the three groups. Results： Mean ADC and rADC of tumor solid part were 1.12 and 1.52 for OD, 1.14 and 1.48 for OA, 1.93 and 2.38 for AC respectively. Mean EDC and rEDC of tumor solid part was 0.33 and 0.70 for OD, 0.32 and 0.71 for OA, 0.15 and 0.34 for AC, respectively. There was significant difference （P〈0.01） between OD and AC, OA and AC in all parameters of tumor solid part. However, no significant difference was found between OD and OA in all parameters of tumor solid part. In peritumor edema, the difference was not significant among the three groups in all parameters. Conclusion： DWI may be helpful in differentiating OD and OA from AC, but not between OD and OA.