A Study For Diagnostic Value Of Multi-parametric Magnetic Resonance Imaging In Transition Zone Prostate Cancer

Objective:1. To investigate the diagnostic value of multi-parametric magnetic resonance imaging (Mp-MRI) in transition zone prostate cancer (PCa) based on prostate imaging reporting and data system(PI-RADS).2. To explore the diagnostic value of multi-parametric MRI imaging features in transition zone prostate cancer (PCa).Methods:1. Twenty three cases of transition zone PCa and33cases of benign prostatic hyperplasia (BPH) confirmed by pathology who underwent T2WI, DWI, and dynamic contrast enhancement(DCE) were retrospectively analyzed. Four combined imaging which contained T2WI, T2WI+DCE, T2WI+DWI, T2WI+DWI+DCE were analyzed based on PI-RADS score. The statistical scores for two physicians were compared by Cohen’s kappa test, and then the average score of transition zone PCa and BPH were calculated and the independent samples t test was used to compare in four combined imaging. ROC curve was drew and areas under the curve (Az) were compared by Z test. The sensitivity, specificity and accuracy of four combined imaging were calculated. ADC values of transition zone PCa and BPH were measured and compared.2. Forty eight cases of transition zone PCa and83cases of benign prostatic hyperplasia (BPH) confirmed by pathology who underwent Mp-MRI were retrospectively analyzed. We compared the relative risk factors between imaging features in Mp-MRI and diagnosis of transition zone PCa by univariate logistic regression analysis and multivariate logistic regression analysis. Receiver operating characteristic curve (ROC) was drew and areas under the curve were compared by Z test.Results:1. In four combined imaging of T2WI, T2WI+DCE, T2WI+DWI, T2WI+DWI+DCE, the scoring results for two physicians had high consistency (P<0.05), the average scores of transition zone PCa in order were3.13±1.18,3.52±1.04,3.96±1.22,3.91±1.27, the average scores of BPH in order were2.18±0.88,2.33±1.05,2.42±1.28,2.27±1.21and scores of transition zone PCa were higher than BPH (P<0.05). The Az values of four combined imaging to diagnose transition zone PCa were in order0.713,0.767,0.798and0.812and there were no significant differences among the groups (P>0.05). In four combined imaging, the sensitivity in order were60.87%,86.96%,91.30%,82.61%, specificity in order were63.64%,54.55%,42.42%,63.64%, and accuracy in order were62.5%,67.86%,62.50%,71.43%. ADC values of transition zone PCa and BPH were (0.952±0.227)×10-3mm2/s,(1.299±0.243)×10-3mm2/s respectively and there were significant differences among two groups (P<0.05).2. Univariate logistic regression analysis showed that lesion shape, signal intensity, signal uniformity, margin of lesion, boundary of transition zone and peripheral zone and prostatic capsule on T2WI, the type of time signal intensity on dynamic contrast enhanced (DCE) and signal intensity and ADC value on DWI were significantly associated with the diagnosis of transition zone PCa (P<0.05), the volume of transition zone was not significantly associated with the diagnosis of transition zone PCa (P>0.05). Through multivariate logistic regression analysis, it was found that lesion shape, intensity uniformity, margin of lesion, prostatic capsule, boundary of transition zone and peripheral zone were risk factors of transition zone PCa on T2WI and lesion shape, intensity uniformity, margin of lesion, boundary of transition zone and peripheral zone, signal intensity and ADC value on DWI were risk factors of transition zone PCa on Mp-MRI. The areas under ROC curve in diagnosis of transition zone PCa on DCE, DWI, T2WI and Mp-MRI were0.666,0.838,0.891,0.923, respectively. It was found that the difference between T2WI and Mp-MRI, DWI were not statistical significance (P>0.05) and the difference among surplus groups were statistical significance (P<0.05).Conclusion:1. Mp-MRI can improve the diagnostic accuracy for the detection of transition zone PCa, which T2WI+DWI+DCE is the best one. The PI-RADS score is a better semi quantitative method for evaluation of transition zone prostate cancer.2. Mp-MRI can improve the detection of transition zone PCa and the diagnostic performance do not significantly increase compared with T2WI. T2WI combined with DWI can be used as a conventional sequence in diagnosis of transition zone PCa and the value of DCE is poor.