Computed Tomographic Findings in Differentiating between Diverticulitis and Colon Cancer

Abstract

Objective: To determine the computed tomographic (CT) findings associated with diverticulitis or colonic cancer, and to evaluate the CT signs that may help in distinguishing between these two diseases.

Methods: Fifty-five CT scans of patients with colonic diverticulitis (n=17) or colonic cancer (n=38) between January 2002 to October 2005 were retrospectively and independently evaluated by two abdominal radiologists who were blinded to the proved diagnosis. Discrepancies of each CT finding were resolved by consensus opinion. CT findings were assessed as follows: location of involved colon, length of involved segment, degree of pericolonic inflammation, pericolonic lymph nodes, thickness and pattern of bowel wall thickening, presence or absence of simple diverticula at the involved colonic segment, inflamed diverticula, intramural sinus tract, fistula, muscular wall hypertrophy, çarrowheadé sign, extraluminal air and bowel obstruction. The inter-observer agreement was assessed with the kappa statistic. The association of consensus opinion of each CT findings with the final diagnosis of colonic diverticulitis or colon cancer were evaluated by using chi-square test and odds ratios.

Results: Bowel wall thickness less than 1 cm (p < 0.0001, odds ratio 32.89, 95% CI 3.31,798.5), presence of simple diverticula at involved segment (p < 0.001, odds ratio 28.13, 95% CI 4.56, 266.11), presence of inflamed diverticula (p = 0.003, odds ratio 15.42, 95% CI 1.46, 386.32) and symmetrical pattern of bowel wall thickening (p < 0.0001, odds ratio 13.07, 95% CI 2.66, 73.36) were the statistically significant CT findings which are found more frequently in colonic diverticulitis than in colon cancer. On the other hand, bowel wall thickness 1 cm or greater, eccentric pattern of bowel wall thickening without evidence of simple diverticula or inflamed diverticula at the involved colonic segment were the statistically significant CT findings seen more frequently in colon cancer than in diverticulitis.

Conclusion: Bowel wall thickness less than 1 cm, presence of simple diverticula at the involved segment, presence of inflamed diverticula and symmetrical pattern of bowel wall thickening were the helpful CT findings in distinguishing colonic diverticulitis from colon cancer. Bowel wall thickness 1 cm or greater, eccentric pattern of bowel wall thickening without evidence of simple diverticula or inflamed diverticula at the involved colonic segment were the useful CT findings in distinguishing colon cancer from colonic diverticulitis.