Glioma grading: sensitivity, specificity, positive and negative predictive values of diffusion and perfusion imaging (Retracted article. See vol. 114, pg. 255, 2013)
Glioma grading: sensitivity, specificity, positive and negative predictive values of diffusion and perfusion imaging (Retracted article. See vol. 114, pg. 255, 2013)
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DOI：
10.1007/s11060-009-9807-6
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发表时间：
2009-08-01
影响因子：
3.9
通讯作者：
Nair, S.
中科院分区：
文献类型：
--
作者：
Arvinda, H. R.;Kesavadas, C.;Nair, S.
目的探讨相对脑血容量(RCBV)、表观弥散系数(ADC)及ADC比值阈值在脑胶质瘤分级中的统计学意义。材料与方法对51例经手术病理证实的原发性脑胶质瘤患者进行常规MRI、动态增强T2加权灌注成像和弥散成像。对影像表现进行回顾性盲法分析，包括血流参数和弥散参数。RCBV测量是从最大灌注区获得的。最小ADC值从肿瘤内最大低信号区域和相应的对侧白质获得。将两种方法测定的肿瘤分级与组织病理学分级进行比较。采用Mann-Whitney检验比较不同肿瘤类型的DWI和PWI。接收器工作特性分析用于确定肿瘤分级的最佳阈值，并计算识别高级别胶质瘤的敏感度、特异度、PPV和NPV。结果统计学分析显示rCBV的阈值为2.91，对判断高级别胶质瘤的敏感性为94.7%，特异性为93.75%，PPV为90.0%，NPV为96.8%。将ADC值98.50 mm(2)/S定义为高级别胶质瘤的阈值，其敏感度、特异度、PPV和NPV分别为90、87.1、81.81和93.10%。低级别和高级别胶质瘤的rCBV比率、ADC值和ADC值有显著差异(P<；0.0001)。结论将PWI和DWI与常规MRI相结合，可提高神经胶质瘤术前影像分级的准确性。RCBV测量在预测胶质瘤分级方面具有最好的诊断性能。ADC值的绝对值或ADC值比值也有助于胶质瘤的术前分级。阈值可在临床环境中用于术前评估肿瘤的组织学分级，并为指导治疗和预测术后患者结果提供一种手段。
Purpose The purpose of our study was to determine the statistical significance of thresholds of relative cerebral blood volume (rCBV), apparent diffusion coefficient (ADC) and ADC ratios in grading cerebral gliomas. Materials and methods In this retrospective study, 51 patients with histopathologically confirmed primary cerebral gliomas who had undergone conventional MR imaging, dynamic contrast-enhanced T2*-weighted perfusion MR imaging and diffusion MR imaging were included. A retrospective blinded analysis of the imaging findings including the perfusion and diffusion parameters was done. The rCBV measurements were obtained from regions of maximum perfusion. Minimum ADC values were obtained from the region of maximum hypointensity within the tumor and from the corresponding opposite white matter. Tumor grade determined with the two methods were then compared with the histopathologic grade. Mann-Whitney tests were performed to compare the DWI and PWI between tumor types. Receiver operating characteristic analyses were performed to determine optimum thresholds for tumor grading and also to calculate the sensitivity, specificity, PPV, and NPV for identifying high-grade gliomas. Results Statistical analysis demonstrated a threshold value of 2.91 for rCBV to provide sensitivity, specificity, PPV, and NPV of 94.7, 93.75, 90.0, and 96.8%, respectively, in determining high-grade gliomas. An ADC value of 98.50 mm(2)/s was defined as a threshold below which tumors were classified as high-grade gliomas and a sensitivity, specificity, PPV, and NPV of 90, 87.1, 81.81 and 93.10% respectively, were obtained. Significant differences were noted in the rCBV ratios, ADC and ADC ratios between low- and high-grade gliomas (P < 0.0001). Conclusion Combining PWI and DWI with conventional MR imaging increases the accuracy of pre-operative imaging grading of glial neoplasms. The rCBV measurements had the most superior diagnostic performance in predicting glioma grade. Absolute ADC values or ADC ratios were also helpful in preoperative grading of gliomas. Threshold values can be used in a clinical setting to evaluate tumors preoperatively for histologic grade and provide a means for guiding treatment and predicting postoperative patient outcome.