Evaluation of suspected soft tissue lesion in the prostate bed after radical prostatectomy using 3T multiparametric magnetic resonance imaging

Purpose: To investigate the usefulness of multiparametric MR imaging (mp-MRI) at 3. T for evaluating suspected soft tissue lesion in the prostate bed after radical prostatectomy (RP). Materials and methods: Forty-three patients with biochemical recurrence (BCR) who received RP underwent mp-MRI at 3. T with a phased-array coil, including T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCE-MRI) and were enrolled in this study. All patients with BCR had a suspected soft tissue lesion in the prostate bed, followed by transrectal ultrasound-guided biopsy. As a control group, 14 consecutive patients without BCR who received RP were also enrolled. Two experienced radiologists independently analyzed four different imaging datasets. Results: For predicting local recurrence, the specificity, accuracy and area under the curve for both readers were significantly greater on all combined imaging datasets than on T2WI alone (P. <. 0.05). The sensitivity of all combined imaging datasets in both readers was not statistically different with T2WI alone (P. >. 0.05), except for combined T2WI and DWI. Inter-reader agreements for the four different imaging datasets were moderate. Conclusion: DCE-MRI or DWI in combination with T2WI at 3. T with a phased-array coil appears to be more useful than T2WI alone in evaluating suspected soft tissue lesion of the prostate bed after RP.