Sector map used in PI-RADS v2. AFS(AS): Anterior Fibromuscular Stroma, CZ: Central Zone, TZ: Transition Zone, PZ: Peripheral Zone, US: Urethral Sphincter. a:anterior, p:posterior, m:medial, l:lateral. From American College of Radiology. MR Prostate Imaging Reporting and Data System version 2.0. Accessed March 2016, from http://www.acr.org/Quality-Safety/Resources/PIRADS/