Magnetic resonance colonography. A form of 'virtual colonoscopy'. It is a relatively new imaging modality intended to provide broadly similar information to to conventional fibre-optic endoscopic colonoscopy. 
Has the advantage over CT colonography that it does not involve ionising radiation. This is an important consideration if a regular population screening programme is contemplated as the cumulative radiation exposure carries its own risk of malignancy. It also allows imaging of other organs in the abdominal and pelvic cavity.