Active crohn’s disease findings include

• Mucosal hyperenhancement
• Wall thickening
• Mural stratification (seeing bowel layers) with prominent vasa recta (comb sign)
• Mesenteric fat stranding

“ CT enterography also has been shown to be more cost effective in the long term assessment and follow-up of patients, especially those with established Crohn’s disease.”
CT Enterography: Principles, Trends, and Interpretation of Findings
Elsayes KM et al.
RadioGraphics 2010; 30:1955-1974

“While diverticulitis of the small bowel is a rare cause of inflammatory disease of the gastrointestinal tract, this condition is associated with a high mortality, which in part is due to a delay in the correct diagnosis. The CT findings in jejunal diverticulitis, although not specific, may suggest this diagnosis. The CT findings in ileal diverticulitis can probably not be differentiated from those of other inflammatory processes in the right lower quadrant. Diverticulitis of the small bowel should be included in the differential diagnosis of intraabdominal inflammatory processes.”
Small-bowel diverticulitis: CT findings
S Greenstein, B Jones, EK Fishman, JL Cameron and SS Siegelman
American Journal of Roentgenology. 1986;147: 271-274

“Jejunal diverticula have characteristic findings on CT, appearing as discrete round or ovoid, contrast-, fluid-, or air-containing structures outside the expected lumen of the small bowel, with a smooth, barely discernible wall and no recognizable small bowel folds. Not infrequently, these structures are seen to communicate directly with an adjoining small-bowel loop, a feature best recognized by scrolling the images. Our experience suggests that jejunal diverticulosis can often be recognized on the basis of the characteristic CT features of this condition.”
Jejunal Diverticulosis: Findings on CT in 28 Patients
Florian Fintelman, Marc S. Levine Stephen E. Rubesin
AJR 2008; 190:1286–1290

“Diverticulosis of the jejunum and ileum is an uncommon entity, with a reported prevalence on conventional barium studies of 0.3-1.9% and at autopsy of 0.3-1.3% . However, a recently published study using enterocylsis found diverticula of the jejunum and ileum in 2.3% of patients studied by this technique. Small-bowel diverticula found incidentally on small-bowel series or barium enema are usually asymptomatic. Acute complications including diverticulitis, perforation, obstruction, and hemorrhage are relatively rare, occurring in 6.5-1 0.4% of patients.”
Small-bowel diverticulitis: CT findings
S Greenstein, B Jones, EK Fishman, JL Cameron and SS Siegelman
American Journal of Roentgenology. 1986;147: 271-274