为了评估在阅读经验不同的读者中，PI-RADSv2.1和PI-RADSv2描述符的表现，21名放射科医师（其中7名有经验的（≥5年）高级医生，7名经验较少的高级医生和7名实习医生）评估了159个预生物检前多参数前列腺MRI上的240个“预定义”病变。他们规定了病变的位置（周边、转移或中央区域）和大小，并使用PI-RADSv2.1和PI-RADSv2描述符对其进行评分。如果需要，他们还会描述并评分“其他”病变。基于每个病变的分析，评估了“预定义”病变，以定向活检为参考；基于每个叶叶的分析，包括“预定义”和“其他”病变，以组合系统性和定向活检为参考。曲线下面积（AUC）量化了诊断临床上显著的癌症（csPCa；ISUP≥2的癌症）的表现。卡帕系数（κ）或一致性相关系数（CCC）评估了读者间的一致性。在每个病变的分析中，位置和大小的读者间一致性为中至好（κ=0.60-0.73）和极好（CCC≥0.80），分别。对于高级医生和实习医生，使用PI-RADSv2.1评分的一致性为中等（κ=0.43-0.47）和一般（κ=0.39）。使用PI-RADSv2.1，实习医生获得了显著较低的AUC（0.74；95％置信区间[95％CI]：0.70-0.79），而经验丰富的高级医生（0.80；95％CI0.76-0.84；p=0.008）没有，经验较少的高级医生（0.74；95％CI0.70-0.78；p=0.75）也没有。与PI-RADSv2相比，PI-RADSv2.1下调了每名读者的17个病变（四分位距[IQR]：6-29），其中2个（IQR：1-3）是csPCa；它升级了每名读者的4个病变（IQR：2-7），其中1个（IQR：0-2）是csPCa。包括每个读者的60个（IQR：25-73）“附加”病变的叶间分析得到了类似的结果。经验对使用PI-RADSv2.1描述符进行病变表征的影响显着。与PI-RADSv2相比，PI-RADSv2.1倾向于下调非csPCa病变，但该效应在读者之间的差异很小。©2023年。作者。

To assess PI-RADSv2.1 and PI-RADSv2 descriptors across readers with varying experience.Twenty-one radiologists (7 experienced (≥ 5 years) seniors, 7 less experienced seniors and 7 juniors) assessed 240 'predefined' lesions from 159 pre-biopsy multiparametric prostate MRIs. They specified their location (peripheral, transition or central zone) and size, and scored them using PI-RADSv2.1 and PI-RADSv2 descriptors. They also described and scored 'additional' lesions if needed. Per-lesion analysis assessed the 'predefined' lesions, using targeted biopsy as reference; per-lobe analysis included 'predefined' and 'additional' lesions, using combined systematic and targeted biopsy as reference. Areas under the curve (AUCs) quantified the performance in diagnosing clinically significant cancer (csPCa; ISUP ≥ 2 cancer). Kappa coefficients (κ) or concordance correlation coefficients (CCC) assessed inter-reader agreement.At per-lesion analysis, inter-reader agreement on location and size was moderate-to-good (κ = 0.60-0.73) and excellent (CCC ≥ 0.80), respectively. Agreement on PI-RADSv2.1 scoring was moderate (κ = 0.43-0.47) for seniors and fair (κ = 0.39) for juniors. Using PI-RADSv2.1, juniors obtained a significantly lower AUC (0.74; 95% confidence interval [95%CI]: 0.70-0.79) than experienced seniors (0.80; 95%CI 0.76-0.84; p = 0.008) but not than less experienced seniors (0.74; 95%CI 0.70-0.78; p = 0.75). As compared to PI-RADSv2, PI-RADSv2.1 downgraded 17 lesions/reader (interquartile range [IQR]: 6-29), of which 2 (IQR: 1-3) were csPCa; it upgraded 4 lesions/reader (IQR: 2-7), of which 1 (IQR: 0-2) was csPCa. Per-lobe analysis, which included 60 (IQR: 25-73) 'additional' lesions/reader, yielded similar results.Experience significantly impacted lesion characterization using PI-RADSv2.1 descriptors. As compared to PI-RADSv2, PI-RADSv2.1 tended to downgrade non-csPCa lesions, but this effect was small and variable across readers.© 2023. The Author(s).