Fig. 3

Examples of applying the grading systems in the validation cohort and the correlation with positive surgical margins after surgery. Magnetic resonance images (from the left to the right) are axial T2-weighted images (AX T2), sagittal T2-weighted images (SAG T2), diffusion-weighted images (DWI) (b value = 2000 s/mm²), and apparent diffusion coefficient (ADC) maps. a–f A 75-year-old man with prostate cancer. Images show the curvilinear contact length of the lesion in the posterior peripheral zone ≥ 20 mm (arrows). The patient was classified as grade 2 by both mrPSM1 and mrPSM2 and was considered to have intermediate risk of PSM. Whole mount pathology (e) and a microscopic view (f) of prostate shows a positive surgical margin at the right posterior. g–l A 62-year-old man with prostate cancer. MRI images show the apex lesion encircling the distal prostatic urethra (arrows) and indicating apex abutting (g–j). The patient was classified as grade 2 by both mrPSM1 and mrPSM2. Whole mount pathology (k) and a microscopic view (l) of prostate show a positive surgical margin at the apex