T2-T2 FLAIR不匹配征象联合扩散和灌注加权成像预测WHOⅡ~Ⅲ级星形细胞瘤IDH突变状态

Prediction of IDH Mutational Status in WHO Grade Ⅱ-Ⅲ Astrocytoma Using T2-T2 FLAIR Mismatch Sign Combined with DWI and PWI

目的探讨T2-T2 FLAIR不匹配征象联合扩散加权成像和灌注加权成像对WHOⅡ~Ⅲ级星形细胞瘤异柠檬酸脱氢酶(IDH)突变状态的诊断价值。资料与方法回顾性分析经手术和病理证实的84例星形细胞瘤的常规MRI、扩散加权成像(DWI)及灌注加权成像(PWI)资料,其中43例IDH突变型星形细胞瘤、41例IDH野生型星形细胞瘤,比较两组患者的T2-T2 FLAIR不匹配征象、相对表观扩散系数(rADC)、最小ADC值(ADCmin)和相对最大脑血容量(rCBVmax)。结果12例T2-T2 FLAIR不匹配征象的病例均为IDH突变组患者。IDH野生组ADCmin和rADC明显低于IDH突变组(P<0.001)。当ADCmin≥0.96时,其鉴别IDH野生型与IDH突变型的敏感度、特异度和受试者工作特征曲线下面积(AUC)分别为76.74%、80.49%和0.85;当rCBVmax<2.53时,其鉴别两者的敏感度、特异度和AUC分别为81.40%、70.73%和0.81。联合T2-T2 FLAIR不匹配征象、DWI和PWI检查鉴别两者的敏感度、特异度和AUC分别为86.05%、80.49%和0.89。结论T2-T2 FLAIR不匹配征象是诊断IDH突变型星形细胞瘤高度特异的征象。联合T2-T2 FLAIR不匹配征象,DWI和PWI有助于准确预测WHOⅡ~Ⅲ级星形细胞瘤的IDH突变状态。

Purpose To investigate the diagnostic value of diffusion weighted imaging(DWI)and perfusion weighted imaging(PWI)combined with T2-T2 FLAIR mismatch sign in predicting IDH mutational status in World Health Organization grade Ⅱ-Ⅲ astrocytomas.Materials and Methods Conventional MRI,DWI and PWI data of 84 patients with surgically and pathologically confirmed astrocytomas were retrospectively analyzed,including 43 cases of IDH mutant astrocytomas and 41 cases of IDH wild-type astrocytomas.T2-T2 FLAIR mismatch signs,relative apparent diffusion coefficient(rADC),minimum ADC(ADCmin)and relative maximum cerebral blood volume(rCBVmax)values were compared between two groups.Results All 12 tumors that presented with T2-T2 FLAIR mismatch sign were IDH mutant astrocytomas.ADCmin and rADC were significantly lower in IDH wild-type astrocytomas group than those in IDH mutant astrocytomas group(P<0.001).With ADCmin≥0.96 as the cut-off value,its sensitivity,specificity and area under the ROC curve(AUC)for differentiating IDH mutant astrocytomas and IDH wild-type astrocytomas were 76.74%,80.49% and 0.85,respectively.With rCBVmax<2.53 as the cut-off value,its sensitivity,specificity and AUC for differentiating IDH mutant astrocytomas and IDH wild-type astrocytomas were 81.40%,70.73% and 0.81,respectively.DWI combined with PWI and T2-T2 FLAIR mismatch sign showed a sensitivity,specificity and AUC of 86.05%,80.49% and 0.89,respectively for differentiating IDH mutant astrocytomas and IDH wild-type astrocytomas.Conclusion T2-T2 FLAIR mismatch sign represents a highly specific imaging biomarker for the diagnosis of IDH mutant astrocytomas.A combination of T2-T2 FLAIR mismatch sign,DWI and PWI is useful for predicting IDH mutations of WHO grade Ⅱ-Ⅲ astrocytomas.