[The value of DCE-MRI in predicting IDH gene mutation of high-grade gliomas]

Objective: To investigate the value of quantitative and semiquantitative parameters of DCE-MRI in predicting IDH gene mutation of high-grade gliomas before the operation. Methods: Twenty-six individuals with surgically and pathologically proved WHO Ⅲ-Ⅳ gliomas collected from April 2016 to June 2019 in First People's Hospital of Changzhou, were divided into two groups, IDH mutation group (7 cases, 27-67 years, 3 males and 4 females,) and IDH gene wild group (19 cases, 42-75 years, 12 males and 7 females) according to the results of molecular pathology. All individuals underwent conventional plain (T(1)WI, T(2)WI), enhanced MR scanning (T(1)WI) and dynamic contrast enhancement (DCE). Four quantitative parameters:volume transfer constant (K(trans)), ratio constant of back flux (Kep), extravascular extracellular space fractional volume (Ve), and blood plasma fractional volume (Vp), and four semiquantitative parameters: time to peak (TTP), maximum concentration (MAX Conc), initial area under the gadolinium concentration-time curve (IAUC) and maximum slope of decrease (MAX Slope) were measured. The independent samples t test (normal distribution and homogeneity of variance) or Mann-Whitney rank sum test (abnormal distribution or heterogeneity of variance) were used to compare the differences of quantitative and semiquantitative parameters between IDH gene mutation group and IDH gene wild type group. Receiver operating characteristic (ROC) curve was used to evaluate the efficiency of quantitative and semiquantitative parameters in predicting IDH gene mutation of high-grade gliomas. Results: The value of K(trans),TTP in IDH mutated group were 0.096 (0.080,0.135)/min and (3.95±0.34) s, respectively. The value of K(trans), TTP in IDH wild type group were 0.168 (0.132, 0.337)/min and (2.58±1.15) s, respectively. The value of K(trans) in IDH mutated group was significantly less than the value of K(trans) in IDH gene wild type group (Z value was -2.168, P value was 0.030). The value of K(trans) in IDH mutated group was significantly greater than the value of K(trans) in IDH gene wild type (Z value was -2.630, P value was 0.007). The area under the ROC curve (AUC) of K(trans) and TTP in predicting IDH gene mutation of high-grade gliomas was 0.782 and 0.842, respectively. The specificity of K(trans) was higher (73.7%), The sensitivity of TTP was the higher (100.0%). Combined K(trans)and TTP were the best for predicting IDH gene mutation of high-grade gliomas, AUC was 0.865. Conclusion: Quantitative and semiquantitative parameters of DCE-MRI can help to predict IDH gene mutation of high-grade gliomas before the operation.