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

Area of Science:

• Radiology and Imaging Science
• Oncology Diagnostics
• Medical Imaging Standardization

Background:

• Multiparametric MRI is crucial for diagnosing prostate cancer.
• The Prostate Imaging - Reporting and Data System (PI-RADS) guideline aids standardization.
• PI-RADS version 2.1, updated in 2019, enhances diagnostic capabilities.

Purpose of the Study:

• To highlight and interpret key updates in PI-RADS version 2.1.
• To assess the clinical implications of PI-RADS 2.1 changes compared to PI-RADS 2.0.
• To provide guidance on the application of the revised PI-RADS scoring scheme.

Main Methods:

• Comparative analysis of PI-RADS 2.1 and PI-RADS 2.0.
• Interpretation of updated image acquisition and interpretation protocols.
• Focus on changes in diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) sequences.

Main Results:

• PI-RADS 2.1 simplifies scoring while maintaining core principles.
• Increased emphasis on DWI in the transition zone is noted.
• Mandatory high b-value (≥1400 s/mm²) and updated central zone assessment are key features.

Conclusions:

• PI-RADS 2.1 introduces significant changes in examination technique and interpretation.
• The strengthened role of DWI in the transition zone aims to improve detection rates.
• Further clinical studies are needed to validate reduced interreader variability and improved detection in the transition zone.