Slow component apparent diffusion coefficient for prostate cancer: Comparison and correlation with pharmacokinetic evaluation from dynamic contrast-enhanced MR imaging

Purpose: Dynamic contrast enhancement (DCE)-MRI has high diagnostic performance of prostate cancer. However, it is preferable to avoid the use of MRI contrast media. A study reported that the diagnosability of the wash-in index of DCE-MRI was equivalent to the intravoxel incoherent motion of the diffusion weighted image. The purpose of this study was to examine the correlation between the slow component apparent diffusion coefficient (ADC) and the wash-out index of the DCE. Materials and methods: Thirty-eight patients diagnosed with prostate cancer by biopsy were enrolled in this study. The fast and slow component ADCs of the DWI were calculated for 76 points of the tumor and the contralateral normal parts. Furthermore, the wash-in and wash-out indices of the DCE-MRI were calculated. The correlations for each calculated index were compared. Results: There was a significant difference between the tumor and the contralateral normal parts for both fast (p = 0.03) and slow component (p < 0.01) ADCs. In addition, the slow component ADC was correlated with the wash-out index (r = 0.64). Conclusion: The slow component ADC was correlated with the wash-out index, and may, therefore, be a suitable substitute for DCE-MRI.