Is PI-RADS Version 2.1 Outdated for Prostate MRI?

Does the Prostate Imaging Reporting and Data System (PI-RADS) version 2.1 need an overhaul?

Debating the issue in a set of point-counterpoint articles, recently published in the American Journal of Roentgenology, researchers noted that a prevailing majority of technical specifications for the PI-RADS system haven’t changed in nearly 10 years, but the system reportedly offers a strong tool for ruling out clinically significant prostate cancer (csPCa).

Here are eight takeaways from the point-counterpoint discussion.

1. In the last decade, only 22 publications focusing on MRI have advocated for changes to the PI-RADS system and the researchers noted that only five of those publications provided metrics to support the impact of the proposed changes for the “whole spectrum of outcomes,” according to lead counterpoint author Leonardo Kayat Bittencourt, M.D., Ph.D, who is affiliated with the Department of Radiology at University Hospitals Cleveland Medical Center in Ohio, and colleagues.

2. Thirty of 35 parameters for PI-RADS technical specifications have not changed since the introduction of PI-RADS version 2 (v2) in 2015, according to the point author Tristan Barrett, MBBS, MD, who is affiliated with the Department of Radiology at the University of Cambridge and Cambridge University Hospitals NHS Foundation Trust Addenbrooke’s Hospital in Cambridge, United Kingdom.

3. Dr. Barrett noted that current Prostate Imaging Quality (PI-QUAL) recommendations suggest that meeting only seven of the aforementioned PI-RADS parameters facilitates optimal quality across T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI sequences.

4. In contrast to a T2-weighted MRI-led approach recommended by the PI-RADS system, Dr. Barrett said recently published research points out that diffusion-weighted imaging MRI (DWI MRI) interpretation of the transition zone prior to T2WI MRI leads to a 36 percent improvement in specificity (90 percent) and a 16 percent increase in inter-reader agreement (73 percent).

5. Dr. Bittencourt and colleagues maintained that the current PI-RADS v2.1 system provides straightforward protocols and acquisition parameters that are “readily implementable” in 1.5 T or higher MRI scanners without the need for proprietary technology.

6. The current PI-RADS recommendations don’t reflect advances in signal-to-noise ratio (SNR) and spatial resolution driven by increased availability of synthetic b-value DWI MRI and the advent of deep learning reconstruction, according to Dr. Barrett.

7. Dr. Barrett noted that current PI-RADS recommendations do not provide guidance on the use of biparametric MRI (bpMRI).

8. Citing a 70-study meta-analysis published earlier this year, the Dr. Bittencourt and colleagues pointed out that the current PI-RADS system has a 93 percent sensitivity for excluding csPCa.