Prostate cancer with seminal vesicle invasion. (a) Axial T2WI showing a right posterolateral peripheral zone tumor (∗) which is contiguous with the adjacent seminal vesicle tubules (arrowheads). According to the TNM staging system, this would be consistent with at least a T3 tumor (Stage III). Prostate cancer with seminal vesicle invasion. (b) Sagittal T2WI showing a right posterolateral peripheral zone tumor (∗) which is contiguous with the adjacent seminal vesicle tubules (arrowheads). According to the TNM staging system, this would be consistent with at least a T3 tumor (Stage III). B: bladder; SV: normal-appearing seminal vesicle tubules. Prostate cancer with seminal vesicle invasion. (c) Coronal T2WI showing a right posterolateral peripheral zone tumor (∗) which is contiguous with the adjacent seminal vesicle tubules (arrowheads). An additional tumor is noted within the contralateral peripheral zone (also ∗). According to the TNM staging system, this would be consistent with at least a T3 tumor (Stage III). B: bladder; SV: normal-appearing seminal vesicle tubules. B: bladder.