MR灌注成像在评价脑内胶质瘤残留或复发方面的价值

The Potential Role of MR Perfusion Imaging in Evaluation of Residual or Recurrent Cerebral Gliomas

目的用受试者操作特性(ROC)分析方法评价常规MR和灌注成像(PWI)对脑内胶质瘤术后早期残存与复发的诊断价值。资料与方法回顾性分析经手术与病理证实的脑内胶质瘤86例,其中术后残留或复发50例,均经二次手术证实;其余36例术后随诊18个月以上无复发表现。所有患者均行常规MRI和PWI,获得相对脑血流容积彩图,并计算肿瘤相对血容积比值。采用Windows98版ROCKIT软件进行ROC分析,使用微软Excel2000软件绘制ROC曲线图。结果86例胶质瘤术后的影像资料经ROC分析显示,常规MR曲线的a值(截距)为0.12,b值(斜率)为0.95,Az为0.5343;结合PWI的方法a值为0.56,b值为1.23,Az为0.6370。两种方法ROC曲线的Az差异有统计学意义(P=0.0001,<0.01)。在胶质瘤术后残存或复发的诊断方面,结合PWI的MRI诊断方法明显优于常规MRI。结论在术后早期,对胶质瘤残存与复发的监测方面,常规MRI结合PWI能明显提高特异性和敏感性。

Objective To investigate the potential role of conventional MR and perfusion weight imaging （PWI） in the determination of recurrent or residual gliomas by receiver operating characteristic （ROC） analysis. Materials and Methods 86 patients with cerebral postoperative gliomas were reviewed retrospectively. 56 cases of postoperative residual or recurrent cerebral gliomas were confirmed by pathology and second surgery. Other 36 cases were appeared as no residual or recurrent sign on MR follow up at least 18 months. All patient were performed with conventional MR and PWI to get relative cerebral blood volume （rCBV） and its color map. Regions of abnormality were identified on conventional MR images by three radiologists and compared with rCBV. ROC analysis was made. Results ROC analysis indicated that there were significant difference （ P 〈 0.01 ） between a single conventional MR and a combination of PWI with conventional MR images groups with a = 0.12, b = 0.95, Az = 0.5343 on conventional MR and with a = 0.56, b = 1.23, Az = 0. 6370 on PWI combining conventional MR imaging. Conclusion Echo planar perfusion imaging appears to have great potential role of improving preoperative evaluation on residual or recurrent gliomas, and a combination of PWI with conventional MR images can greatly improve diagnostic accuracy and specificity in early postoperative period of gliomas.