Diffusion-weighted imaging (DWI) has been gaining prominence in improving the detection of prostate cancer. Intravoxel incoherent motion (IVIM) MR imaging, which uses a bi-exponential model to extract perfusion-related information from the DWI signal, has been reported to separate molecular diffusion and microcirculation of blood within the capillaries utilizing low b-values^1,2. Tumor perfusion has been evaluated with dynamic contrast enhanced (DCE)-MRI in the routine clinical scans³, but it needs intravenous contrast agent administration. The purpose of the study was to apply the IVIM technique on detecting the prostate cancer and investigate the diffusion and perfusion coefficients among prostate cancer (PCa), normal peripheral zone (PZ) and benign prostatic hyperplasia (BPH).This study was approved by local institutional review board. 28 subjects (mean 70±4years; 16 PCa lesions, 22 PZ, 22 BPH) with TRUS biopsy after MR examination were recruited into this study. The study was performed on a 3.0T MRI scanner (Ingenia, Philips Healthcare, Best, the Netherlands) with 16-channel SENSE coil. The examinations included axial and coronal T2WI, IVIM. The IVIM protocol was performed with a single-shot SE-EPI sequence with TR/TE of 6000/54ms, slice thickness=3mm, FOV=240×240mm, matrix size=96×96 , slices=22. The diffusion weighting was performed along three orthogonal directions at 11 b values of 0, 10, 20, 30, 50, 75, 100, 250, 500, 750 and 1000s/mm². Regions of interest (ROIs) were placed within proven prostate cancer, PZ and BPH by referencing histopathological results to calculate the parameters of IVIM. Data were fitted with IVIM bi-exponential model by using DWI post-processing software performed in a proprietary programming environment (PRIDE; Philips Medical Systems). The diffusion coefficients (D), perfusion fractions (f) and the perfusion-related diffusion Coefficient (D*) was compared by one-way AVONA and Kruskal-Wallis test using IBM SPSS Statistics 20.0 (Armonk, New York, USA). P<0.05 indicated a significant difference. All diffusion parameters obtained are summarized on Table 1. The diffusion coefficient in prostate cancer were significantly lower than those found in the PZ and BPH (P <0.05); but no statistical differences of diffusion coefficient were found between PZ and BPH (P>0.05) (Figure 1). The perfusion fractions in prostate cancer were significantly higher than those in the PZ (P <0.05); The perfusion fractions in prostate cancer were lower than the BPH; but there were no statistical differences (P=0.052) (Figure 2,3). There were no significant differences in the prostate cancer, PZ and BPH for the D*, which had large SDs. Some studies reported that diffusion coefficients were decreased in prostate tumors compared to benign tissues^4,5, which was consistent with our study. The reduction of D in cancer reflects intracellular restricted diffusion. However, perfusion fractions of tumors were unexpectedly lower in these studies, which is contrary to what has been known from DCE studies and angiogenesis in tumors⁶. But our study found that the f were significantly higher in prostate cancer than that in PZ which is consistent with some DCE-MRI studies in tumors. The perfusion fractions in prostate cancer were lower than those found in the BPH although there were no obvious statistical differences (P=0.052). Future work will recruit more volunteers and subjects for further validation. Bi-exponential analysis can provide more detailed information on perfusion and diffusion of prostate cancer noninvasively without intravenous contrast agent administration. It may be very helpful in differentiating prostate cancer from BPH in the central gland and assisting in the diagnosis and monitoring therapy efficacy of prostate cancer.