title: The impact of helical computed tomography on the diagnosis of unsuspected inflammatory bowel disease in the large bowel.
abstract: Inflammatory bowel diseases (IBD) are diagnoses that can be easily overlooked clinically. The aim of this study was to investigate if CT is able to make a contribution to the identification of previously unsuspected cases of IBD. We retrospectively identified cases in which the possibility of an IBD was raised in CT reports (over a 4-year period), by utilising a keyword search of the radiology database. Cases with a previously known or suspected IBD were rigorously excluded by review of case notes, and endoscopic, radiological, histological and microbiological findings. The CT images of the identified cases were reviewed by a blinded observer to document the extent of bowel wall thickening, the location of lesion(s), and presence of peri-colic fat abnormality, ascites and/or collections. The observer also attempted to corroborate the presence, and to identify the type, of IBD based on the CT appearances alone. Thirty-five cases (out of approximately 19,000 body CTs performed) of clinically unsuspected IBD were identified, of which 27 underwent further investigation. An IBD was confirmed in 48% (13 of 27): Crohn's disease (n=6), ulcerative colitis (n=2), pseudomembranous colitis (n=3) and other (n=2), of which 70% (9 of 13) were correctly typed by the reviewer. Inflammatory bowel disease was not substantiated in the remainder (14 of 27), although 7 of these had other bowel pathologies: diverticular disease (n=4); and carcinoma (n=3). Prospectively determining the presence, and furthermore type, of IBD on CT is challenging largely because of the considerable overlap in the appearances of the individual IBDs and indeed of normality. Nevertheless, CT is able to identify clinically unsuspected cases and radiologists should be alert to this treatable and not infrequently elusive diagnosis.
authors.affiliation: Department of Radiology, Addenbrooke's NHS Trust, Cambridge, UK.
authors.forename: G
authors.initials: G
authors.lastname: Markose
authors.forename: C S
authors.initials: CS
authors.lastname: Ng
authors.forename: A H
authors.initials: AH
authors.lastname: Freeman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003093:Colitis, Ulcerative / Q000000981:diagnostic imaging; D003287:Contrast Media; D003424:Crohn Disease / Q000000981:diagnostic imaging; D004761:Enterocolitis, Pseudomembranous / Q000000981:diagnostic imaging; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000000981:diagnostic imaging*; D007422:Intestines / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed
chemical_list: D003287:Contrast Media