Application Value Of Multiparameter Magnetic Resonance Imaging And PI-RADS Scoring System In The Diagnosis Of Prostate Cancer

Purpose:To compare the diagnostic accuracy of biparametric MRI(bpMRI)and multiparametric MRI(mpMRI)for prostate cancer(PCa)and clinically significant prostate cancer(csPCa),and to explore the application value of dynamic contrast-enhanced(DCE)MRI in prostate imaging.Methods and materials:This study retrospectively enrolled 235 patients with suspected PCa in our hospital from January 2016 to December 2017,all lesions were histopathologically confirmed.The lesions were scored according to the Prostate Imaging Reporting and Data System version 2(PI-RADS v2).The bpMRI(T2-weighted imaging[T2WI],diffusion-weighted imaging[DWI]/apparent diffusion coefficient ADC])and mpMRI(T2WI,DWI/ADC and DCE)scores were recorded to plot the receiver operating characteristic curve(ROC).Area under the curve(AUC),accuracy,sensitivity,specificity,negative predictive value(NPV),and positive predictive value(PPV)for each method were calculated and compared.The patients were further stratified according to bpMRI scores(bpMRI≥3,and bpMRI=3,4,5)to analyze the difference in DCE between PCa and non-PCa lesions(as well as between csPCa and non-csPCa)for the application value of DCE MRI.Results:The AUC values of bpMRI and mpMRI for PCa were comparable(0.790[95%CI:0.732-0.840]and 0.791[95%CI:0.733-0.841],respectively).The accuracy,sensitivity,specificity,PPV and NPV of bpMRI for PCa were 76.2%,79.5%,72.6%,75.8%,and 76.6%;and the values for mpMRI were 77.4%,84.4%,69.9%,75.2%,and 80.6%,respectively.For the diagnosis of csPCa,the AUC values of bpMRI and mpMRI were similar(0.781[95%CI:0.722-0.832]and 0.779[95%CI:0.721-0.831],respectively).The accuracy,sensitivity,specificity,PPV and NPV of bpMRI for csPCa were 74.0%,83.8%,66.9%,64.8%,and 85.0%;and 73.6%,87.9%,63.2%,63.2%,and 87.8%for mpMRI.For patients with bpMRI score≥3,the difference in DCE between PCa and non-PCa,and between csPCa and non-csPCa were both statistically significant,a positive DCE results were more common in PCa and csPCa lesions(both P=0.001).Further stratification analysis showed that for patients with bpMRI score=4,DCE had statistically significant difference between PCa and non-PCa,and between csPCa and non-csPCa(P=0.003,and P<0.001,respectively).Conclusion:The diagnostic accuracy of bpMRI is comparable with that of mpMRI in the detection of PCa and identification of csPCa.DCE is helpful in further identifying PCa and csPCa lesions in patients with bpMRI≥3,especially bpMRI=4,which may be conductive to achieve more accurate PCa risk stratification.Purpose:To compare the diagnostic performance of PI-RADS version 2.1(PI-RADS v2.1)and PI-RADS v2 for transition zone prostate cancer(TZPC),and analyze its performance for readers with different experience levels.Methods:Eighty-five patients with suspected prostate cancer who underwent biopsy after MRI scan between January and December 2017 were retrospectively enrolled.One junior radiologist(reader A,1 year of experience in using PI-RADS v2)and one senior radiologist(reader B,6 years of experience in using PI-RADS v2)independently reviewed and assigned a score for each lesion according to PI-RADS v2.1 and v2.The template-guided transperineal prostate biopsy was used for standard of reference.To compare the diagnostic performance of the two methods,the AUC was calculated.The sensitivity,specificity,and accuracy were calculated at predefined positive values(PI-RADS≥3).The interreader agreement and frequency of prostate cancer for each PI-RADS category were also calculated.Results:Among the 85 patients,27 had prostate cancers,and 25 were clinically significant prostate cancer(csPCa).The AUC values for diagnosing clinically significant prostate cancer significantly increased with PI-RADS v2.1 for reader B(0.766 vs.0.902,P=0.009).The specificity and accuracy for both readers also increased with PI-RADS v2.1(specificity:reader A,41.7%vs.78.3%and reader B,33.3%vs.81.7%;accuracy:reader A,52.9%vs.76.5%and reader B,48.2%vs.83.5%,all P<0.05).The interreader agreement was good for both versions.The percentage of prostate cancer decreased in lower PI-RADS categories(PI-RADS 2)and increased in higher PI-RADS categories(PI-RADS 3-4).Conclusion:Compared with PI-RADS v2,PI-RADS v2.1 may improve radiologists’diagnostic performance for TZPC.