Preliminary Application Of Modified Bi-parametric MRI Scoring Method Based On PI-RADS V2 In The Diagnosis Of Prostate Lesions

Part I The value of modified Bi-parametric MRI scoring method based on PI-RADS V2 in the diagnosis of Prostate LesionsObjective:Four improved scoring methods,including Mp-MRI(multi-parametric MRI)prostate imaging reporting and data method V2,PI-RADS V2 scoring method and Bp-MRI(Bi-parametric MRI)(based on PI-RADS V2),are used to score and diagnose the group research cases.At the same time,two doctors carry out consistency analyses on the consistency of prostate infection focus diagnostic scores of the above five scoring methods and compare the diagnostic efficacy of different scoring methods of Bp-MRI so as to select the effective and simplified Bp-MRI scoring method with similar diagnostic efficacy with Mp-MRI.Materials and methods:Prostate Mp-MRI examination is done to patients with possible prostate diseases who were hospitalized in the Affiliated Second Hospital,Suzhou University from January,2016 to June 2018.They are scanned by 3.0T MRI equipment.The scanning sequence include the intact T2WI,DWI and DCEI sequences.At the same time,pathological diagnosis results(methodatic puncture biopsy of prostate)and clinical,imaging and pathological data of cases will also be obtained.Inclusion criteria and exclusion criteria(refer to the main contents)of this group research will also be included into the research cases.Two radiology doctors(genitourinary subspecialty)will diagnose each case independently without knowing pathological results.According to PI-RADS V2 scoring standard,two doctors select one infection focus(refer to main contents for standards for selecting infection focuses)of each case and give the score of each single sequence of T2WI,DWI and DCE.Besides,places of infection focus,their score results at each sequence and the maximum diameter of the infection focus are recorded.Finally,comprehensive score scores are obtained by the following five scoring methods:Method 1:Scoring results are obtained by using Mp-MRI(scoring sequences include T2WI,DWI and DCEI)PI-RADS V2 scoring method.Method 2:the infection focus of peripheral zone of the prostate is obtained by using Bp-MRI(scoring sequences include T2WI and DWI)PI-RADS V2 improved scoring method.T2WI replaces DCEI sequence in giving scores.When the DWI sequence of the infection focus is 3 points,the T2WI sequence is>4 points.Finally,one point is added to the final comprehensive score to get 4 points.T2WI sequence is ?3 points.The final comprehensive score is unchanging,which is 3 points.The score of transition zone infection focus of the prostate is obtained according to PI-RADS V2 standard.Method 3:Bp-MRI(scoring sequences include T2WI and DWI)PI-RADS V2 improved scoring method is used.T2WI replaces DCEI sequence to score peripheral zone infection focus of the prostate.When the DWI sequence of the infection focus is 3 points,T2WI sequence is>5 points.One point is added to the final comprehensive score to get 4 points and the T2WI sequence is?4 points.The final comprehensive score is unchanging,which is 3 points.The score of transition zone infection focus of the prostate is obtained according to PI-RADS V2.Method 4:Bp-MRI(scoring sequences include T2WI and DWI)PI-RADS V2 improved scoring method is used.Other sequences of the peripheral zone infection focus of the prostate are not used to replace DCE sequence.The DWI sequence score is the final score.The score of the transition zone infection focus of the prostate is obtained according to PI-RADS V2 standard.Method 5:Bp-MRI(scoring sequences include T2WI and DWI)PI-RADS V2 improved scoring method is used.Other sequences of the infection focus of peripheral zone of the prostate are not used to replace DCE sequence.The DWI sequence score is the final score.When the T2WI score of the transition zone infection focus of the prostate is 3 points,the DWI score is>4 points.One point is added to the final comprehensive score to get 4 points and DWI is<3 points.The final comprehensive score is unchanging,which is 3 points.No matter the infection focus is located in the peripheral zone or transition zone,the maximum diameter of the infection focus is>10mm.Then,rise the final comprehensive score of 4 points to 5 points to get the scoring results.Cohen's Kappa test is used to evaluate the consistency of the diagnostic assessment of the above prostate infection focuses done by five scoring methods used by two radiologists.Then,scoring results of the five methods will be compared with the pathological diagnosis to draw the curve for five scoring methods' being used to diagnose prostate cancer and the prostate cancer ROC curve with clinical significance.Besides,AUC values of ROC curve of scores obtained by the five methods and the sensitivity,specificity,accuracy,positive predictive value,negative predictive value and yoden index will also be obtained to evaluate the efficiency of the five scoring methods in diagnosing prostate cancers and prostate cancer with clinical significance.Besides,the statistical analysis method of DeLong is also used to judge the efficiency of the five scoring methods in diagnosing prostate cancers and their difference in diagnosing prostate cancer with clinical significance.Results:197 cases are researched in this group.The consistency analysis of the above five scoring methods(based on PI-RADS V2)in their diagnosing and scoring prostate infection focus show that the two doctors all show good consistency of the above scoring methods.Kappa values of Method 1 and Method 5 are 0.686,0.691,0.648,0.68 and 0.675 respectively.The analysis of scoring results of the above five methods in diagnosing prostate cancer and the analysis of ROC curve for prostate cancer with clinical significance show that AUC values of ROC curve for prostate cancer diagnosed according to scores of the five scoring methods based on PI-RADS V2(Mp-MRI and Bp-MRI)are Method 1(0.898),Method 2(0.889),Method 5(0.882),Method 4(0.875)and Method 3(0.872)respectively(from large to small).The AUC values of ROC curve for prostate cancer with clinical significance are Method 1(0.940),Method 2(0.928),Method 5(0.911),Method 4(0.908)and Method 3(0.897)respectively(from large to small).Among them,the differences of AUC values of ROC curve obtained by using Method 1 and Method 2 in diagnosing prostate cancer and the analysis of ROC curve for prostate cancer with clinical significance have no statistical significance(P>0.05);the difference of AUC values by using Method 1 and Method 5 in diagnosing prostate cancer has no statistical significance(P>0.05),but their difference in diagnosing prostate cancer with clinical significance has statistical significance(P<0.05);the differences of AUC values obtained by using the scoring method and Method 1 in diagnosing prostate cancer and prostate cancer with clinical significance have statistical significance(P<0.05).Conclusion:The four improved scoring methods based on PI-RADS V2 Bp-MRI can effectively test prostate cancer and prostate cancer with clinical significance.Among them,scoring method 2(Bp-MRI;T2WI replaces DCEI sequence;the infection focus is located on the peripheral zone and DWI is 3 points;T2WI score of 4 points is regarded as the threshold value and the comprehensive score has one point added)has the similar diagnostic efficiency with PI-RADS V2(Mp-MRI)in their diagnosing prostate cancer and prostate cancer with clinical significance.It can simplify the sequence composition,reduce the scanning time and doctors' reading time and remove the potential risk of gadolinium contrast agent.Therefore,it is an efficient and simplified scoring method in prostate MRI examination of prostate cancer and prostate cancer with clinical significance.It is has obvious clinical practical significance and popularization value to reduce the great MRI examination loads of China.Part 2:Discussion on correlation between Bp-MRI improved scoring based on PI-RADS V2 and Gleason scoring for prostate cancerObjective:Discuss the correlation between diagnostic score results obtained by four improved scoring methods of Mp-MRI scoring method and Bp-MRI based on PI-RADS V2 and those obtained by Gleason scoring for prostate cancer.Analyze their effects on diagnosis of low-risk and moderately high risk prostate cancers.Materials and methods:Clinical,imaging and pathological data of prostate Mp-MRI examination cases of patients with possible prostate diseases who were hospitalized in the Affiliated Second Hospital,Suzhou University from January,2016 to June 2018 are collected.They are scanned by 3.0T MRI equipment.The scanning sequence include the intact T2WI,DWI and DCEI sequences.At the same time,pathological diagnosis results(methodatic puncture biopsy of prostate)and clinical,imaging and pathological data of cases will also be obtained.Inclusion criteria and exclusion criteria(refer to the main contents)of this group research will also be included into the research cases.The biopsy pathology of prostate method is diagnosed as prostate cancer.At the same time,they also get the Gleason scoring results,which can meet the inclusion criteria and exclusion criteria for researches of this group(refer to the main contents).All Mp-MRI sequence images of prostate cancer cases included in this group research are scored and evaluated.There are five scoring methods,including PI-RADS V2(Mp-MRI)and Bp-MRI(four improved scoring methods)(from Method 1 to Method 5,ditto).According to Gleason scoring,the inclusion cases belong to low-risk group(GS score=6 points)and moderately high risk group(GS scoree?7 points).Then,Spearman grade is used to analyze and evaluate the correlation between diagnosis and scoring results obtained by the five above scoring methods based on PI-RADS V2 and those obtained by Gleason scoring for prostate cancer.Results:92 prostate cancer cases are included in this group,including 26 low-risk groups(GS=6 points)and 66 moderately high risk groups(GS?7 points).Scores obtained by five scoring methods(Mp-MRI and four improved scoring methods of Bp-MRI)based on PI-RADS V2 are related to Gleason scoring for prostate cancer(r value from Method 1 to Method 5 is 0.553,0.531,0.448,0.464 and 0.453 respectively).Conclusion:This research indicates that the scores obtained by using Method 1(Mp-MRI)and Method 2(based on PI-RADS V2 Bp-MRI improved scoring method)is well related to the Gleason scoring for prostate cancer.They can reflect the invasive degree of the prostate cancer to some degree,therefore,they can help the formulation and prognosis judgment of clinical prostate cancer diagnosis and treatment programs.