Diagnostic Accuracy of lateral Abdominal Radiographs among Paediatric Patients in Detecting Hirschsprung Disease

Abstract

Purpose: The aim of this study was to determine the diagnostic accuracy of lateral abdominal radiographs in the detection of Hirschsprung disease (HSCR) in paediatric patients compared with rectal biopsy as the standard. Methods: This retrospective study was performed in cases with clinical suspicion of HSCR that had undergone lateral or cross-table prone lateral abdominal radiographs and subsequent rectal biopsies at a tertiary hospital in Metro Manila, Philippines. Reversal of the rectosigmoid index (RSI) on a lateral abdominal radiograph without or with a transition zone was interpreted as positive for HSCR. The radiographic findings were correlated with histopathology. Results: A total of 72 cases were included. Age ranged from 4 days to 12 years with a mean of 16 months. In all, 62 cases (86%) were positive for HSCR on biopsy, 39 of which had reversed RSI. Ten patients (14%) were negative for HSCR on biopsy, seven of which showed no reversal of the RSI. Overall, the diagnostic accuracy of the lateral abdominal radiograph was 64%. Sensitivity, specificity, positive predictive value, and negative predictive value were 63%, 70%, 93%, and 23%, respectively. Conclusion: The presence of a reversed RSI on a lateral or cross-table prone lateral abdominal radiograph had a high positive predictive value, indicating a high likelihood of HSCR. Therefore, such views are reliable tools in predicting HSCR in infants and young children. Rectal biopsy should be done for confirmation but patients may no longer need to undergo contrast enema.