Computed tomography of diverticulitis.

Six cases of diverticulitis were studied by means of pelvic computed tomography (CT) and contrast enema. CT is effective in defining the intramural and extracolonic component of diverticulitis; abscess formation in the extracolonic space resulted in consistent changes in the contour of the opacified urinary bladder. Inflammatory extracolonic masses were imaged on CT as low or mixed-attenuation lesions frequently containing pockets of gas. Bladder wall thickening and edema, as well as contour asymmetry of the opacified and distended bladder, were reliable indicators of pericolonic or extracolonic extension of diverticular disease. Contrast enema and sigmoidoscopy are inherently limited in the evaluation of diverticulitis; CT of the pelvis reveals secondary changes outside the mucosa and bowel wall, CT directly images the inflammatory mass and associated changes in pelvic anatomic relationships. CT findings of pelvic inflammatory mass are not specific for abscess of diverticular origin; however, CT interpretation is reliable and confident since it is directed by the supporting findings on contrast enema. Integrated study by CT and contrast enema effectively defines the extent of disease in patients with diverticulitis. Summary evaluation of these studies has a serious impact on the choice of medical or surgical management.