Is Oral Contrast Beneficial for Visualization of the Appendix in Low-Weight Children?

Purpose: It has been shown that oral contrast does not improve the diagnostic accuracy of Computed Tomography (CT) for appendicitis in pediatric patients; however, the cohorts in these studies were not stratified by weight or body mass index. The purpose of this study is to assess the benefit of oral contrast administration for identifying the appendix in younger children in the lower weight quartile. Materials and Methods: This retrospective study comprised 100 patients (2–10 years) in lower weight quartile who had intravenous contrast-enhanced CT of the abdomen and pelvis, 37 of which with oral contrast, and 63 without. A pediatric radiologist and a pediatric radiology fellow independently assessed whether the appendix was visualized or not. In case of discrepancy, an additional pediatric radiologist was the “tie-breaker.” Chi-squared test was used to compare the proportion of visualized appendix between the groups (with and without oral contrast). Inter-rater reliability was determined using Cohen’s Kappa coefficient. Results: There was no significant difference in the visualization of the appendix between the group with oral contrast and without ( P = 1). The Cohen Kappa coefficients were .33 (.05, .62) and .91 (.73, 1.00) for the “no oral” and “oral” groups, respectively, yielding evidence of a difference ( P = .007). Conclusions: There was no significant difference in the visualization of the appendix using CT with or without oral contrast in low-weight pediatric patients. The inter-rater reliability, however, was significantly higher in the group given oral contrast. Additional studies assessing the value of oral contrast for the sole indication of appendicitis may provide clearer results.