Fig. 5

Multiparametric magnetic resonance image of a 69-year-old patient who underwent radical prostatectomy (serum prostate-specific antigen 8.3 ng/ml, apparent diffusion coefficient [ADC] 1.140). An axial T2-weighted image (T2WI) (a) and dynamic contrast-enhanced image (b) indicate an approximately 1.3 cm, heterogeneous, obscured, marginated nodule with mild enhancement in the right transition zone (arrows), resulting in a T2WI score of 3. Diffusion-weighted imaging (DWI) (b = 1000) (c) demonstrated subtle iso-signal intensity at the corresponding nodule with low signal intensity on an ADC map (d), resulting in a DWI score of 3. This lesion was categorized as 3 according to PI-RADS v2.1 but as 3A according to PI-RADS v2.1-B. The patient underwent radical prostatectomy, which confirmed transition-zone cancer with a Gleason score of 7 (4 + 3). The procedure revealed crowded irregular glands with at least a wisp of stroma between each gland (e). This was a false-negative case first categorized with a T2 score of 3 and DWI score of 3. The final category was determined to be 3 based on v2.1 and 3A based on v2.1-B, which is pathologically confirmed malignancy