The Value Of Multi-parameters DWI For Differentiating The Gleason Grade Of Prostate Cancer

Objective 1.To evaluate histogram analysis of intravoxel incoherent motion(IVIM)for discriminating the Gleason grade of prostate cancer(PCa).2.To investigate diagnostic performance of diffusion kurtosis imaging(DKI)with histogram analysis for stratifying aggressiveness of prostate cancer(PCa).Materials and Methods A total of 158 patients pathologically confirmed as having clinically significant PCa(size>0.5 cm),48 patients underwent preoperative DW-MRI b of 0–900 s/mm2,Data was post-processed by mono-exponential and IVIM model for quantitation of apparent diffusion coefficients(ADCs),perfusion fraction f,diffusivity D and pseudo-diffusivity D*.The other 126 pathology-confirmed PCa in 110 patients underwent DW-MRI b of 0-2100 s/mm2 was post-processed by DKI.Histogram analysis was performed by outlining entire-tumor regions of interest(ROIs)from histological–radiological correlation.The ability of imaging indices to differentiate low-grade(LG,Gleason score(GS)? 6)from intermediate/high-grade(HG,GS>6)PCa was analyzed by ROC regression.Results 1.For IVIM analysis,eleven patients had LG tumors(18 foci)and 37 patients had HG tumors(42 foci)on pathology examination.HG tumors had significantly lower ADCs and D in terms of mean,median,10 th and 75 th percentiles than LG PCa(p<0.05).Histogram D showed relatively higher correlations(?=0.641 – 0.668 vs.ADCs: 0.544 – 0.574)with ordinal GS of PCa;and its mean,median and 10th percentile performed better than ADCs did in distinguishing LG from HG PCa.2.For DKI analysis,there were 49 LG-tumor and 77 HG-tumor at pathologic findings.HG-PCa had significantly lower ADCs,lower DK diffusivity(Dapp)and higher kurtosis coefficient(Kapp)in mean,median,10 th,and 90 th percentile,with higher Dapp in skewness and kurtosis than LG-PCa(p < 0.05).10 th ADCs,10 th Dapp and 90 th Kapp showed relatively higher Az,Youden index and positive likelihood ratio(LR+)in stratifying aggressiveness of PCa against other indices.90 th Kapp showed relatively higher correlation(?>0.6)with ordinal GS of Pca,significantly higher Az,sensitivity and specificity(0.889;74.1%;93.9%)than 10 th Dapp(0.765;61.0%;79.6%;p < 0.05),and higher Az and specificity than 10 th ADCs(0.738;71.4%;p < 0.05)in differentiating LG-PCa from HG-PCa.Conclusion 1.It is feasible to stratify the pathological grade of PCa by IVIM with histogram metrics.D performed better in distinguishing LG from HG tumor than conventional ADCs.2.It demonstrated a good reliability of histogram DKI for stratifying aggressiveness of PCa.90 th Kapp had better diagnostic performance in differentiating LG-from HG-PCa.