Related Experiment Video
Updated: Dec 7, 2025
Introduction of an Integrated Pathology Image Management, Artificial Intelligence, and Reporting System
Published on: July 11, 2025
PI-RADS Version 2.1: A Critical Review, From the AJR Special Series on Radiology Reporting and Data Systems
Andrei S Purysko1, Ronaldo H Baroni2, Francesco Giganti3,4
1Section of Abdominal Imaging and Nuclear Radiology Department, Imaging Institute and Glickman Urological and Kidney Institute, Cleveland Clinic, 9500 Euclid Ave, Mail Code JB-322, Cleveland, OH 44145.
Abstract:
PI-RADS version 2.1 updates the technical parameters for multiparametric MRI (mpMRI) of the prostate and revises the imaging interpretation criteria while maintaining the framework introduced in version 2. These changes have been considered an improvement, although some issues remain unresolved, and new issues have emerged. Areas for improvement discussed in this review include the need for more detailed mpMRI protocols with optimization for 1.5-T and 3-T systems; lack of validation of revised transition zone interpretation criteria and need for clarifications of the revised DWI and dynamic contrast-enhanced imaging criteria and central zone (CZ) assessment; the need for systematic evaluation and reporting of background changes in signal intensity in the prostate that can negatively affect cancer detection; creation of a new category for lesions that do not fit into the PI-RADS assessment categories (i.e., PI-RADS M category); inclusion of quantitative parameters beyond size to evaluate lesion aggressiveness; adjustments to the structured report template, including standardized assessment of the risk of extraprostatic extension; development of parameters for image quality and performance control; and suggestions for expansion of the system to other indications (e.g., active surveillance and recurrence).
Insights
PI-RADS version 2.1 enhances prostate cancer detection using multiparametric MRI (mpMRI) but requires further refinement. Key areas for improvement include protocol standardization, clearer criteria for specific prostate zones, and advanced quantitative assessments for better cancer evaluation.
Area of Science:
- Radiology
- Oncology
- Medical Imaging
Background:
- Prostate cancer diagnosis relies heavily on multiparametric MRI (mpMRI).
- PI-RADS (Prostate Imaging—Reporting and Data System) provides a standardized framework for interpreting prostate mpMRI.
- Version 2.1 of PI-RADS introduces updates to technical parameters and interpretation criteria.
Purpose of the Study:
- To review the updates in PI-RADS version 2.1 for prostate cancer assessment.
- To identify areas for improvement and unresolved issues within the revised PI-RADS framework.
- To discuss potential enhancements for future PI-RADS versions.
Main Methods:
- Review of PI-RADS version 2.1 guidelines and technical parameters.
- Analysis of revised imaging interpretation criteria for various prostate zones.
- Discussion of emerging issues and areas needing further validation and clarification.
Main Results:
- PI-RADS v2.1 improves mpMRI interpretation but presents new challenges.
- Need for optimized mpMRI protocols for 1.5-T and 3-T systems.
- Clarification required for transition zone, DWI, DCE-imaging, and central zone criteria.
- Systematic reporting of background parenchymal enhancement is necessary.
- New PI-RADS M category proposed for unclassifiable lesions.
- Inclusion of quantitative parameters and structured reporting adjustments are suggested.
Conclusions:
- PI-RADS v2.1 represents an advancement in prostate mpMRI but requires further refinement.
- Future iterations should address protocol optimization, criterion clarification, and quantitative assessment.
- Expansion to other clinical indications like active surveillance and recurrence is recommended.
