Appendix in children with cystic fibrosis: US features

PURPOSE: To evaluate the ultrasonographic (US) appearance of the appendix in children with cystic fibrosis but who were asymptomatic for appendicitis. MATERIALS AND METHODS: Between March 2001 and March 2002, 31 children (14 boys, 17 girls; mean age, 9.5 years; range, 2-16 years) with cystic fibrosis underwent graded-compression US of the appendix. The recordings were analyzed in consensus by two radiologists specialized in US. The overall appendiceal diameter and change in diameter during graded compression, wall dimensions, contents of material in the lumen, and periappendicular fat were evaluated. The exclusion criterion was abdominal pain at the time of investigation. RESULTS: In all but one patient, the appendix was visualized with US. The diameter of the appendix ranged from 4.0 to 14.5 mm (mean, 8.3 mm). In 25 patients (83.3%), the appendix measured more than 6.0 mm. In six patients, the diameter of the appendix changed when graded compression was applied. Mucoid material was found in the lumen in 27 of 30 patients. No wall thickening occurred, and concentric layer structures of the wall were intact. No involvement of the neighboring mesenteric or omental fat was encountered. CONCLUSION: The appendiceal diameter was enlarged in the majority of children examined. The lumen contained mucoid contents. Therefore, the diameter of the appendix alone may not be a parameter for diagnosing appendicitis in patients with cystic fibrosis. (C) RSNA, 2004.