MR扩散和灌注加权成像在脑WHOⅡ级胶质瘤鉴别诊断中的价值  

Diffusion and Perfusion Weighted MR Imaging in Differentiation of Grade Ⅱ Gliomas

作　　者：李晓光[1] 康厚艺[2] 张伟国[2] 

机构地区：[1]安徽蚌埠医学院 [2]第三军医大学大坪医院野战外科研究所放射科,重庆400042

出　　处：《临床放射学杂志》2014年第3期325-329,共5页Journal of Clinical Radiology

基　　金：第三军医大学临床科研基金资助项目(编号:2009XLC29);重庆市研究生教育教学改革研究重点项目(编号:Yjg110227);重庆市自然科学基金重点项目(编号:cstc2012jjB10028)

摘　　要：目的评价扩散加权成像及动态磁敏感灌注成像在脑内WHOⅡ级少突胶质瘤、少突-星形细胞瘤和星形胶质细胞瘤中的鉴别诊断价值。方法回顾性分析经术后病理证实的46例脑WHOⅡ级胶质瘤,包括21例星形细胞瘤(AC)、17例少突胶质细胞瘤(OD)和8例少突-星形细胞瘤(OA)。分别测量肿瘤实质相对表观扩散系数(rADC)、最大相对脑血容量灌注(rCBVmax)值,分别对3组肿瘤各组数据进行统计分析,采用受试者工作特征(ROC)曲线确定AC与OD/OA鉴别诊断阈值,敏感性、特异性及准确性,并采用Pearson相关分析判断各肿瘤rADC与rCBVmax相关性。结果 AC、OD及OA组肿瘤实性rADC值分别为2.09、1.51、1.60,AC组与OD、OA组差异有统计学意义(P<0.01,P<0.01),OD及OA组组间差异无明显统计学意义。AC、OD及OA组肿瘤实质rCBVmax值分别为1.43、3.34、2.77,OD组与AC组差异有统计学意义(P<0.01),OD与OA组之间差异无统计学意义。ROC曲线分析表明,以rADC 1.94为阈值,鉴别AC与OD/OA诊断敏感性为76.2%,特异性为100%,准确性为81.9%;以rCBVmax 2.15为阈值,鉴别AC与OD/OA诊断敏感性96.0%,特异性为81.0%,准确性为88.7%。AC组rADC与rCBVmax呈负相关(P<0.01),OD或OA组以及OD/OA组rADC与rCBVmax均无相关性。结论扩散和灌注加权成像区分脑WHOⅡ级OD、OA与AC间均具有一定的价值,但在OD与OA方面均有一定的局限性,对于鉴别AC与OD/OA方面,rADC值具有较高的特异性,但鉴别诊断准确性rCBVmax具有较高的价值。Objective To assess the value of diffusion weighted imaging （DWI） and perfusion weighted imaging （PWI） in the differentiation of intracranial grade Ⅱ gliomas. Methods forty six patients with pathologically proved low grade glioma were retrospectivly analyzed. The gliomas were divided into three groups： 22 astrocytomas （AC）, 16 oligodendrogliomas （OD） and 8 oligodendroastrocytomas （OA）. The apparent diffusion coefficient （ADC） and Cerebral Blood Volume （CBV） values in solid part of each tumor were measured, relative ADC （rADC） and relative CBV （rCBV） was calculated and analyzed among the three groups. The threshold of differential diagnosis, sensitivity , specificity and accurancy among AC and OD/OA were deterrnined using receiver operating characteristic curve. The correlation between rADC and rCBVmax in tumor was determined using Pearson analysis. Results rADC of solid part of tumor were 2.09,1.51 and 1.60 in AC,OD and OA, respectively, rCBV of solid part was 1.43,3.34, 2.77 in AC,OD and OA respectively. There was significant difference （P 〈 0.01 ） of rADC and rCBV among AC, OD and OA. However, no significant difference was found of all parameters between OD and OA. Using 1.94 as the threshold value of rADC, the diagnostic sensitivity, specificity and accurancy of AC and OD/OA were 76.2%, 100% and 81.9% respectively. Using 2.15 as the threshold value of rCBVmax, the diagnostic sensitivity, specificity and accurancy were 100%, 81.0% and 88.7% respectively. There wasnegative correlation between rADC and rCBVmax in AC group （ P 〈 0.01 ） , but no correlation in OD or OA group and OD/ OA group. Conclusion Both DWI and PW1 may be helpful in differentiating OD and OA from AC, but there were some difficuhies between OD and OA. rADC value has higher specificity, rCBVmax has higher diagnostic accuracy in differentia- ting AC from OD/OA.

关 键 词：磁共振成像 扩散加权成像 灌注加权成像 低级别胶质瘤 

分 类 号：R739.41[医药卫生—肿瘤] R445.2[医药卫生—临床医学]