The most characteristic lesions and radiologic signs of Crohn disease of the small bowel: air enteroclysis, MDCT, endoscopy, and pathology

Abstract

This pictorial essay describes the most characteristic lesions and radiologic signs of Crohn disease of the small bowel: nodular lymphoid hyperplasia, abnormal mucosal folds, villous pattern, aphthous ulcerations, linear ulcerations, cobblestone pattern, string sign, target sign, comb sign, creeping fat, sinus tracts, fistulas, and abscesses. Each description includes the definition, a correlation with the pathologic findings, an explanation of the possible physiopathologic mechanism, sample radiologic images with air enteroclysis or MDCT, the correspondence with the endoscopic findings when possible, and a list of differential diagnoses.

Bildgebung gastrointestinaler Entzündungen

“…Eine besonders ausgeprägte perienterale Fettgewebsverdichtung im Verhältnis zu einer geringeren Darmwandverdickung ist bei einer Divertikulitis, einer Appendicitis epiploica, einerAppendizitis sowie einem omentalen Infarkt zu finden [28]. Entzündungsreaktion mit vermehrter Fibrosierung sowie eine longitudinale Kontraktion der Muskularis propria sein [29]. Dadurch ist bei radiologischen Untersuchungen eine Verlagerung sowie Distanzierung der umliegenden Darmschlingen zu beobachten.…”

MR Enterography of Inflammatory Bowel Disease with Endoscopic Correlation

“…Progressive inflammation results in the formation of transmural ulcers (28). The aphthous ulcers seen with early-manifesting CD may enlarge and coalesce to form the characteristic linear transmural ulcers seen with CD (Fig 4e) (23,28).…”

“…Progressive inflammation results in the formation of transmural ulcers (28). The aphthous ulcers seen with early-manifesting CD may enlarge and coalesce to form the characteristic linear transmural ulcers seen with CD (Fig 4e) (23,28). Linear ulcers tend to develop on the mesenteric border during the early phase of disease; however, over time the inflammation will spread to involve the antimesenteric border (28).…”

“…The aphthous ulcers seen with early-manifesting CD may enlarge and coalesce to form the characteristic linear transmural ulcers seen with CD (Fig 4e) (23,28). Linear ulcers tend to develop on the mesenteric border during the early phase of disease; however, over time the inflammation will spread to involve the antimesenteric border (28). Although mural fibrosis is a feature of fibrostenotic disease, it is interesting that the mesenteric border also tends to have a higher degree of fibrosis and resultant retraction, with relative sparing of the antimesenteric border (18,28).…”

“…Linear ulcers tend to develop on the mesenteric border during the early phase of disease; however, over time the inflammation will spread to involve the antimesenteric border (28). Although mural fibrosis is a feature of fibrostenotic disease, it is interesting that the mesenteric border also tends to have a higher degree of fibrosis and resultant retraction, with relative sparing of the antimesenteric border (18,28). Consequently, the antimesenteric border tends to be more stretchable and can expand to form sacculations, which have been classically described with CD (18).…”