PI-RADS 2.1 – Image Interpretation: The Most Important Updates and Their Clinical Implications

Abstract

Background Multiparametric magnetic resonance imaging (MRI) of the prostate plays a central role in the diagnosis of patients with suspected prostate cancer. The increasing distribution and application of the guideline for the standardization of image acquisition, evaluation, and reporting (Prostate Imaging – Reporting and Data System, PI-RADS), which was updated in 2019 to version 2.1, contributes to the success of the technique.

Materials and Methods The most important updates of PI-RADS version 2.1 presented in 2019 compared to the previous version PI-RADS 2.0 are highlighted and interpreted with regard to their clinical implications.

Results PI-RADS version 2.1 aims to simplify the application of the scoring scheme without changing the basic concept of dominant sequences (DWI in the peripheral zone, T2 in the transition zone). Of particular importance are the increasing role of diffusion-weighted imaging in the transition zone, the now mandatory high b-value of at least 1400 s/mm², and new information on the assessment of the central zone and the anterior fibromuscular stroma.

Conclusion PI-RADS version 2.1 published in 2019 addresses a number of changes to the previous version, including both the examination technique and image interpretation. Prospective clinical studies have yet to prove the extent to which the goals of reducing interreader variability and increasing the detection rate in the transition zone will be achieved.

Key Points: 

• The new PI-RADS version 2.1. includes changes regarding image interpretation and examination technique

• The role of diffusion-weighted imaging is strengthened in the transition zone

• An ultra-high b-value of at least 1400 s/mm² is mandatory according to PI-RADS 2.1

• Biparametric MRI is not recommended for general application

Citation Format

• Beyer T, Schlemmer H, Weber M et al. PI-RADS 2.1 – Image Interpretation: The Most Important Updates and Their Clinical Implications. Fortschr Röntgenstr 2021; 193: 787 – 795

Key words

prostate - PI-RADS - prostate cancer - uroradiology - MR imaging

Publication History

Received: 04 March 2020

Accepted: 10 November 2020

Article published online:
21 December 2020

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