Intra- and interreader reproducibility of PI-RADSv2: A multireader study

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• The Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) is widely used for prostate MRI since 2015.
• While interreader reproducibility has been examined, intrareader reproducibility of PI-RADSv2 remains understudied.

Purpose of the Study:

• To assess the intra- and interreader reproducibility of PI-RADSv2 in evaluating intraprostatic lesions using multiparametric MRI (mpMRI).

Main Methods:

• Retrospective analysis of 102 biopsy-naïve patients undergoing prostate mpMRI (3T).
• Four readers from different institutions scored lesions twice (4-week interval) using PI-RADSv2.
• Reproducibility quantified using Kappa (κ) statistics, specific agreement (P_o), and intraclass correlation coefficient (ICC) for measurements.

Main Results:

• Moderate intrareader reproducibility (κ=0.43-0.67) and substantial agreement (P_o=0.60-0.77) were observed.
• Poor to moderate interreader reproducibility (κ=0.24, P_o=0.46) was found.
• Experienced readers demonstrated better interreader agreement than intermediate readers.
• Intrareader ICC for lesion measurement was 0.82, while interreader ICC was 0.71.

Conclusions:

• PI-RADSv2 demonstrates moderate intrareader and poor interreader reproducibility for prostate MRI lesion scoring.
• Moderate interreader reproducibility was noted for lesion measurements.
• Findings highlight the need for enhanced, standardized reader training to improve PI-RADSv2 consistency.