Multiparametric MR imaging of the prostate at 1.5-T without endorectal coil using an 8 channel pelvic phased array: Is it still a viable option?

Abstract

Introduction: The purpose of our work was to evaluate the feasibility of prostate multiparametric MR imaging at 1.5-T without endorectal coil using an 8 channel pelvic phased array coil.

Material and methods: A total of 154 patients who underwent mp-MRI were retrospectively included. Patients received a standardized mp-MRI, compliant with 2012 European Society of Uro-Radiology guidelines, with 1·5 T magnetic field strength and an 8 channel pelvic phased-array coil. Two blinded readers graded the image quality of mp-MRI on a three-point scale and they scored the prostate lesions according to PI-RADS v2. All PI-RADS of 4 or 5 underwent biopsy. A third radiologist and a pathologist verified the correspondence between the MRI images and the results of the biopsy.

Results: 64 (41.6%) patients showed a Pi-rads of 4 or 5. At biopsy, 79.7% showed a Gleason score ≥7, 12.5% showed a Gleason score of 6 and 7.8% showed a negative biopsy. In the group of Pi-rads ≤ 3, 12 patients underwent a biopsy with the following results: negative biopsy in 33.3%, atypical Small Acinar Proliferation in 16.7%, prostatic intraepithelial neoplasia in 25% and indolent PCa 25%. Mp-MRI in the identification of clinically significant cancer provided a low percentage of false positive (7.8%) while in 79.7% of cases it was capable to detect clinically significant prostate cancer. In 92.2% of patients mp-MRI identified a prostate cancer with a Gleason score ≥6. The inter-reader agreement was excellent in defining both the quality of the examination and the PI-RADS category (k = 0.83 and k = 0.70, respectively).

Conclusions: mp-MRI at 1.5-T without endorectal coil using an 8 channel phased array is an appropriate tool for early detection of clinically significant prostate cancer.

Implications for practice: 8 channel pelvic phased array is still an appropriate tool for early detection of clinically significant prostate cancer and for obtaining a reduction in overdiagnosis of indolent PCa.

Keywords: Multiparametric MRI; Prostate.