This is to be achieved using Model Based Iterative Reconstruction (MBIR) which has been shown to result in diagnostically acceptable low-dose CT imaging while providing a significant reduction of ionising radiation dose to the patient. The authors aim to apply MBIR to their low dose protocol, and to facilitate diagnostic quality CT scanning of the abdomen and pelvis at an effective dose approximately four times less than what would normally occur with an abdominopelvic CT in patients with suspected active Crohn's disease (CD).