Related Experiment Video For Imaging, disease, method, classification system
Updated: Apr 3, 2026
A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Multiplanar versus axial measurement of prostate lesion size: agreement and impact on PI-RADS v2.1 categorization and
Thitinan Chulroek1, Ratchaya Ariyasaksakul2
1Department of Diagnostic Radiology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand.
Purpose:
To evaluate whether measurement of prostate lesion size on sagittal or coronal imaging planes influences PI-RADS v2.1 categorization and histopathologic correlation compared with axial measurement.
Methods:
In this single-center retrospective study, 261 prostate lesions categorized as PI-RADS 4 or 5 underwent subsequent targeted MRI/TRUS fusion biopsy or prostatectomy. Lesion size was measured as maximal axial diameter (MAD) and maximal coronal or sagittal diameter (MCSD). Lesions were subsequently categorized according to PI-RADS v2.1 using these measurements. The agreement between MAD and MCSD was assessed using a Bland-Altman analysis. Measurement reliability and interobserver agreement were evaluated using intraclass correlation coefficients (ICC). Kappa statistics were used to assess agreement in PI-RADS categorization for clinically significant prostate cancer.
Result:
Bland-Altman analysis demonstrated minimal bias and strong agreement between MAD and MCSD measurements for the whole prostate (mean difference 0.28 mm; 95% limits of agreement - 2.62 to 3.19 mm), with similar results in both the peripheral and transition zones. Intraclass correlation analysis showed excellent reliability between measurements (ICC = 0.93). Agreement in PI-RADS categorization between MAD and MCSD was almost perfect (κ = 0.931). Reclassification from PI-RADS 4 to 5 occurred in 1.74% of lesions when using MCSD, and all reclassified lesions demonstrated clinically significant prostate cancer on histopathology.
Conclusion:
MAD and MCSD measurements of prostate lesion size demonstrate excellent agreement and highly concordant PI-RADS categorization. Although reclassification is uncommon, evaluation of the sagittal or coronal planes may provide additional value for selected lesions with craniocaudal elongation, where the maximal tumor extent may not be fully represented on axial images.
