Radiological insights into diverticulitis: Clinical manifestations, complications, and differential diagnosis

Diverticulitis is an infection of the diverticular sacs protruding from the intestinal wall. It typically presents as elevated inflammatory markers and left lower quadrant abdominal pain. Although clinical symptoms and biomarkers are essential for diagnosis, imaging methods, particularly computed tomography (CT), are critical due to the inability to perform endoscopic procedures in the acute phase because of the risk of perforation. Various classification systems that include imaging findings have been developed. The most recent and widely accepted system is the Sartelli classification, which is endorsed by the World Society of Emergency Surgery. This classification describes stages of diverticulitis ranging from edematous bowel wall thickening and phlegmon in the adjacent mesentery to microperforation, localized or distant abscess formation, and generalized peritonitis with free fluid and air. Imaging findings are also pivotal in diagnosing and managing complications such as abscesses, pylephlebitis, fistulas, and gastrointestinal bleeding. Moreover, imaging can differentiate diverticulitis from infectious colitis, epiploic appendagitis, ischemic colitis, colorectal carcinoma, and inflammatory bowel disease. This review focuses on the radiological findings of diverticulitis. We specifically discuss CT imaging and emphasize its clinical manifestations, significant complications, and differential diagnosis.