Transition Zone

A normal appearing TZ (rare) or a round, completely encapsulated nodule (“typical nodule”)

A mostly encapsulated nodule or a homogeneous circumscribed nodule without encapsulation (“atypical nodule”) or a homogeneous mildly hypointense area between nodules.

Heterogeneous signal intensity with obscured margins (arrow). Includes others that do not qualify as 2, 4, or 5.

Lenticlular (arrow) or noncircumscribed, homogeneous, moderately hypointense, and <1.5 cm in greatest dimension.

Same as 4, but ≥ 1.5cm in greatest dimension (arrows) or definite extraprostatic extension/invasive behavior