Diagnostic Value Of DKI Combined With IVIM For Prostate Cancer And Its Correlation With The Eighth Edition Of AJCC Staging And Grading

Objectives: 1.To analyze the value of diffusion kurtosis imaging(DKI)combined with intra voxel incoherent motion imaging(IVIM)for differential diagnosis of prostate cancer(PCa).2.To explore the correlation between DKI as well as IVIM-related quantitative parameters and the clinical pathological staging and grading of PCa in the 8th edition of American Joint Committee on Cancer(AJCC).Methods: 1.Our study consisted of 69 prostatic diseases including 33 cases of PCa and 36 cases of benign prostatic hyperplasia(BPH)confirmed by puncture or radical resection.All patients underwent conventional T1 WI,T2WI,diffusion weighted imaging(DWI),DKI,and IVIM sequence scans to obtain parameters of apparent diffusion coefficient (ADC),pure apparent diffusion coefficient(Pure-ADC /D),standard apparent diffusion coefficient(Standard-ADC/Ds),fast apparent diffusion coefficient(fast-ADC/D*),perfusion fraction(frcation of fast apparent diffusion coefficient,f),mean diffusion kurtosis(MK),axial kurtosis(Ka),radial kurtosis(Kr),and mean diffusion coefficient(MD)of the lesions.The receiver operating characteristic curve(ROC)was used to evaluate the differential diagnosis of BPH and PCa by the above parameters.P < 0.05 was considered statistically significant.2.The DKI and IVIM images of 33 patients with PCa were retrospectively analyzed.The original images were imported into the AW 4.6 workstation of the GE 750 discovery superconducting 3.0T MR configuration,resulting in a post-processing diagram of the IVIM and DKI parameters.The self-developed software was used to load the post-processing image.Two abdominal radiologists with more than 10 years’ experience in MRI diagnosis of genitourinary system were blinded to the final pathological results,and were asked to analyze the images.The ADC,D,Ds,D*,f,MK,Ka,Kr and MD values of the lesions were measured,and then multiplied by the relevant conversion coefficients to obtain the final experimental data.One-way analysis of variance(ANOVA)was used to compare the quantitative parameters of different PCa groups with different clinical pathological stages and grades in the 8th edition of AJCC.Spearman correlation analysis was used to correlate the parameters with the clinical pathological grades of the 8th edition of AJCC.Multiple comparisons between groups using Bonferroni correction.P<0.05 was considered statistically significant.Results: 1.There were significant differences in MK,MD,D and f values between BPH and PCa groups(P<0.001).There was a significant negative correlation between the MK value in the DKI model and the D value in the IVIM model.The correlation coefficient is r=-0.881,P<0.001.2.ROC curve analysis showed that the diagnostic efficiency of MK value was the highest for PCa based on conventional MRI,and the area under the curve(AUC)was 0.979.The combined D and MK values have an AUC of 0.987.3.There were significant differences in parameters of MK,Ka and MD between different clinical pathological grades groups of the 8th edition of AJCC(P<0.05).There were significant differences in parameters of MK,Ka,Kr and MD between different Gleason grading groups(P<0.05).Spearman correlation analysis showed that the MD value was negatively correlated with the clinical pathological grades of AJCC(r=-0.515,P=0.002).MK,Ka and Kr values were positively correlated with Gleason grading of PCa(r=0.977,0.863 and 0.735,P<0.001),while the MD value was moderately negatively correlated with Gleason grading of PCa(r=-0.512,P=0.002).4.There were significant differences in D values between different clinical pathological grades groups of the 8th edition of AJCC(P<0.05).There were significant differences in D,Ds and f values between different Gleason grading groups(P<0.05).Spearman correlation analysis: D value was negatively correlated with the clinical pathological grades of AJCC(r=-0.495,P=0.003);D value was negatively correlated with Gleason grading(r=-0.669,P < 0.001),Ds value was moderately negatively correlated with Gleason grading(r=-0.567,P=0.001),and f value showed a moderately negative correlation with Gleason grading(r=-0.485,P=0.004).There was no significant difference in D* values between differe nt clinical pathological grades groups of AJCC as well as between different Gleason grading groups(P>0.05).Conclusions: 1.D value in the IVIM model and the MK value in the DKI model show high sensitivity and specificity in diagnosis of PCa.The combination of the two parameters has higher diagnosis efficiency,which is helpful for differential diagnosis of BPH and PCa.2.MD value in the DKI model and the D value in the IVIM model are significantly correlated with the clinical pathological grades of the 8th edition of AJCC.MK value in the DKI model and the D value in the IVIM model are significantly correlated with Gleason grades.It is expected that the degree of malignancy of PCa and the prognosis of patients will be quantitatively evaluated under non-invasive conditions.