Figure 2.

The 41 segmentation model proposed for prostate with enlargement of transition zone and presence of median intravescical lobe: fourthy-one sectors/regions: thirty-eight for the prostate, two for the seminal vesicles and one for the external urethral sphincter are identified. In comparison to 39 segmentation model proposed by PI-RADS v2, the 41 segmentation model adds two segments (right and left) of an intravescical median lobe.

TZ: transizon zone; CZ: central zone; PZ: peripheral zone; AS: anterior stroma; SV: seminal vesicle; ML: median lobe.