USE OF AIR ENEMA RADIOGRAPHY TO ASSESS DEPTH OF ULCERATION DURING ACUTE ATTACKS OF ULCERATIVE-COLITIS

Background Acute colitis is usually assessed by means of plain abdomin al radiographs, the diagnostic utility of which can be enhanced by bar ium enema. Colonoscopy can also be useful. The latter methods may be l aborious and carry risk, We describe a radiographic technique using ai r as the contrast medium to show mucosal or deeper ulceration. Methods Of 60 patients undergoing colectomy for acute ulcerative colitis, 35 had air enema radiography and 14 had plain films with sufficient amoun t of spontaneously occurring gas to allow visualisation of the mucosa, during the 10 days before surgery. The degree of inflammation on air enema films and the extent of histopathological ulceration in colectom y specimens were independently graded and compared with each other. De pth of ulceration was compared with clinical data including a preopera tive risk stratification, the APACHE II score. Findings The degree of inflammation on air enema radiography correlated significantly with de pth of ulceration at histopathological examination (r(s) 0.61, p < 0.0 01). Presence of mucosal changes had a close association with deep ulc eration extending into the muscularis propria layer or beyond (p < 0.0 01). Air enema radiography had a high sensitivity (0.91) for presence of and specificity (0.75) in the exclusion of deep ulceration, with po sitive and negative predictive values of 0.88 and 0.80. 42 of 49 patie nts were correctly classified as regards deep ulcers. The correlation between higher preoperative APACHE II scores and severity of histopath ological colitis was weak (r(s) 0.30, p < 0.05). Interpretation Air en ema radiography reliably assesses the presence of colonic ulceration i n patients with an acute attack of ulcerative colitis. It is a first-l ine investigation to assess the presence of deeper ulceration in acute colitis.