Objective To investigate the correlation between the parameters of mono-and bi-exponential diffusion weighted imaging(DWI)models and EGFR gene mutation as well as Ki-67 expression.Methods 51 patients with lung adenocarcinoma confirmed pathologically were retrospectively analyzed.All patients were examined by multi-b value DWI lung MRI,and were classified into EGFR mutation group and wild-type group according to whether EGFR gene mutation oc-curred,or divided into high and low Ki-67 expression groups based on Ki-67 expression levels.ADC value of the mono-ex-ponential DWI model and parameters(D,D*,and f)of bi-exponential DWI model(IVIM)were obtained.The correlation between the above DWI parameters and expression of EGFR and Ki-67 were evaluated,the differences of each DWI parame-ters between different EGFR mutations groups or Ki-67 expression groups were compared,and the ROC curves for evaluating the predictive efficacy of statistically correlated parameters on EGFR or Ki-67 were drawn.Results Among 51 patients with lung adenocarcinoma,25 were EGFR mutation type and 26 were wild-type,and the expression of Ki-67 was high in 28 cases and low in 23 cases.The D value was positively correlated with EGFR gene mutation status with statistic significance(r=0.368,P＜0.05).There was a low negative correlation between ADC value and Ki-67 index(r=-0.298,P＜0.05)and a moderate negative correlation between D value and Ki-67 index(r=-0.508,P＜0.05).The D value in the EGFR mutations group was significantly higher than that in the wild type group(P＜0.05).The ADC and D value of the high Ki-67 group were significantly lower than those of the low Ki-67 group(P＜0.05).The D value showed a good performance in discriminating EGFR mutation group and wild-type group with an area under the ROC curve(AUC)of 0.712.When D≥1.03 × 10-3mm2/s,the diagnosis tended to be EGFR gene mutation.The AUC of ADC and D value for distinguishing high from the low Ki-67 group was 0.726、0.859,respectively(Z=1.979;P=0.048).When ADC＜1.22 × 10-3mm2/s or D＜1.06 × 10-3mm2/s,a diagnosis of high Ki-67 expression was preferred.Conclusion The D value was positively corre-lated with EGFR gene mutation status.There was a low negative correlation between the ADC value and Ki-67 expression and a moderate negative correlation between the D value and Ki-67 level.Therefore,mono-and bi-exponential DWI models are helpful in individualized evaluation of patients with lung adenocarcinoma,and the performance of bi-exponential DWI model was better than that of mono-exponential models.
Lung adenocarcinomaIntravoxel incoherent motionMagnetic resonance imagingEpidermal growth fac-tor receptorKi-67 index
NETL
NSTL
维普
万方数据
