The PI-RADS Steering Committee—an international collaboration of the American College of Radiology (ACR), European Society of Urogenital Radiology (ESUR), and AdMeTech Foundation—released an update, Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1). PI-RADS, now in its third iteration, has been adopted worldwide as the foundation for the acquisition, interpretation, and reporting of prostate MRI exams performed to detect and diagnose prostate cancer.

The updated version, PI-RADS v2.1, introduces several modifications while maintaining the original framework of assigning scores to individual imaging sequences and using these scores to derive, on a lesion by lesion basis, an overall likelihood that an abnormal area in the prostate represents clinically significant prostate cancer. It is anticipated that the adoption of PI-RADS v2.1 modifications will reduce inter-reader variability and strengthen reporters’ confidence in assigning a PI-RADS score to any lesion.

“The goals of updating the PI-RADS assessment system for prostate MRI to version 2.1 are to further reduce imaging interpretation variability and errors, enhance communication with referring clinician and patients, enable the collection of standardized data, and ultimately yield better patient outcomes,” says Jeffrey Weinreb, MD, FACR, co-chair of the PI-RADS steering committee.

PI-RADS v2.1 revises the following:

  • Technical Specifications for T2W, DWI, and DCE sequences
  • Clarification in Measurement of Prostate Volume
  • Revised Anatomical Sector Map
  • Clarification in Interpretation Criteria for Central Zone (CZ) and Anterior Fibromuscular Stroma (AFS), Transition Zone (TZ)—what to score and how to score.
  • Revision of criteria for DWI scores 2 & 3
  • Clarification of distinction between (+) and (-) DCE d
  • Discussion of bi-parametric MRI (bpMRI) where DCE sequences are omitted

Continuing research on the value and limitations of PI-RADS v2.1 is strongly encouraged, to provide an evidence base for future refinements. The updated PI-RADS v2.1 2019 is now available on and European Urology .