Diagnostic Value Of Bi-parametric MRI Of PI-RADS As An Adjunct To PSAD Detection Of Prostate Cancer

ObjectiveTo investigate the value of diagnosis for clinically significant prostate cancer(c sPCa)by combining bi-parametric magnetic resonance imaging(B-MRI)with prostate specific antigen density(PSAD)on the basis of the Prostate Imaging Reporting and Data System verison 2.0(PI-RADS V2).Materal and MethodsEighty patients of prostate cancer and 47 of benign prostate hyperplasia(BPH)that were confirmed by biopsy pathology in our hospital were scanned with 3.0B-MRI(T2-weighted imaging and diffusion-weighted imaging).Using the PI-RADS V2 score,MR imagings were assessed and recorded by two diagnostic physicians who double-blinded to the indication respectively.The value of prostate specific antigen(PSA),prostate volume and the value of PSAD were collected and calculated.Using the pathological results as the golden standard,the data of different group were analyzed using method of statistics.ResultsThe average values of PSAD and PI-RADS V2 score were 1.19±0.88,3.90±1.00 in PCa group and 0.38±0.40,2.30±0.55 in BPH group respectively.The difference of two groups was statistically significant(PSAD,t=5.91,P<0.05;PI-RADS,t=10.10,P<0.05).The area under curve(AUC)for PSAD,PI-RADS V2 and the combined diagnosis were 0.794,0.894 and 0.949.When 0.15 of the PSAD was served as csPCa with the cutoff point,the diagnostic sensitivity,specificity,positive predictive value(PPV)and the negative predictive value(NPV)were 98.68%,30%,68.18% and 94.12% respectively.When 3 of the PI-RADS was served as csPCa with the cutoff point,the diagnostic sensitivity,specificity,positive predictive value(PPV)and the negative predictive value(NPV)were 90.67%,69.23%,81.00% and 83.72%respectively.The diagnostic specificity was 80% when PI-RADS V2 score and PSAD combined.When the two combined,a PI-RADS V2 score of 3 and PSAD?0.15,or PI-RADS V2 score?4 and PSAD?0.15,the positive rate of csPCa were 72% and92%;When a PI-RADS V2 score < 3 and PSAD?0.15,or PI-RADS V2 score?4 and PSAD<0.15,the positive rate of csPCa were 20% and 25%.In contrast,when a PI-RADS V2 score ?3 and PSAD<0.15,there was no csPCa detected.ConclusionIt is very useful to predict biopsy outcome,classify the severity of the disease and provide even higher efficiency in detecting csPCa when combining B-MRI PI-RADS V2 with PSAD.Patients with a PI-RADS v2 score of ?3 and PSA density of <0.15 may avoid unnecessary biopsies.