Imaging update: acute colonic diverticulitis.

Because the incidence of colonic diverticulosis is high in the general population, incidental asymptomatic diverticulosis is commonly seen on radiology imaging studies. However, diagnostic imaging performed specifically for diverticular disease is essentially limited to imaging of suspected acute colonic diverticulitis (ACD) and its complications. The clinical diagnosis of ACD can be challenging, and imaging has become an essential tool to aid in diagnosis, assess severity of disease, and aid in treatment planning. Computed tomography (CT) has replaced contrast enema as the imaging procedure of choice for diverticulitis. Ultrasound has also been successfully used for diagnosis, and magnetic resonance imaging (MRI) has significant potential as a radiation-free imaging test for acute colonic diverticulitis.