Objective:

The aim of this study is to demonstrate the utility of a post-contrast late sequence in multiparametric magnetic resonance imaging (RMMP) to characterize PI-RADS II lesions.

Materials and methods:

The RMMPs performed between January 2015 and December 2016 were retrospectively analyzed. The RMMP protocol was based on the recommendations of the PI-RADS version 2, and a late acquisition was added, after the dynamic post-contrast. The reports were reviewed under the version 2.1.

Results:

31 patients with PI-RADS II lesions in the peripheral zone were selected, who were in prostate specific antigen follow-up and had histological confirmation of chronic prostatitis. A late enhancement of the lesion was evidenced in all patients. According to the histopathological results, 30 had chronic prostatitis and the remaining benign tissue (fibromuscular tissue).

Discussion:

Chronic prostatitis does not show early enhancement, and presents late enhancement due to its fibrous connective tissue. In RMMP, prostatitis may mimic prostate cancer. Adding a late sequence only adds 150 seconds to the study and could help to resolve those uncertain cases categorized as PI-RADS III using traditional sequences because the late enhancement of the lesion is highly suggestive of an inflammatory process (PI-RADS II).

Conclusion:

The presence of late enhancement is a useful tool to perform an adequate diagnosis of a PI-RADS II lesion in the peripheral zone, helping to avoid an unnecessary biopsy.