Water enema multidetector CT technique and imaging of diverticulitis and chronic inflammatory bowel diseases

BACKGROUND: Water enema multidetector computed tomography (WE-MDCT) is currently considered the most accurate imaging modality to provide high-resolution multiplanar visualisation of the colonic wall and surrounding structures. METHODS: This pictorial review presents our experience with WE-MDCT applications outside colorectal tumour staging, particularly for investigating diverticular disease and chronic inflammatory bowel diseases. A detailed explanation of the technique is provided, including patient preparation, the acquisition protocol, and study interpretation. RESULTS: WE-MDCT allows accurate preoperative visualisation of diverticular disease, acute and complicated diverticulitis. Ulcerative, indeterminate, or Crohn’s colitis can be assessed including longitudinal distribution, mural thickening and enhancement patterns, pseudopolyps, associated perivisceral changes, adjacent organ involvement, and features suggesting carcinoma. Elective WE-MDCT represents a useful complementary technique in patients with impossible, incomplete, or inconclusive endoscopy, can allow study of a stricture’s features and the upstream bowel, and helps planning medical, endoscopic, or surgical treatments. CONCLUSION: Urgent WE-MDCT with limited or no bowel preparation may prove useful in acutely symptomatic patients, as it may obviate a risky or contraindicated endoscopy, can determine disease severity, and allows making correct therapeutic choices. TEACHING POINTS: • Water enema multidetector CT provides high-resolution multiplanar visualisation of the colonic wall. • WE-MDCT allows accurate visualisation of diverticular disease, acute and complicated diverticulitis. • In chronic inflammatory bowel diseases WE-MDCT depicts the distribution, mural and perivisceral changes. • Elective WE-MDCT usefully complements incomplete endoscopy to assess strictures and upstream colon. • Urgent WE-MDCT with limited or no bowel preparation in acute diseases may obviate endoscopy.