Diagnostic performance of saline-aided ultrasound in the detection of colorectal polyps in children

OBJECTIVES: This study aimed to evaluate the diagnostic performance of saline-aided gastroenteric ultrasound (US) for detecting colorectal polyps in pediatric patients. METHODS: In this single-center, retrospective study (April 2018 to November 2023), we analyzed 466 patients with suspected colorectal polyps. All patients underwent conventional US followed by diagnostic colonoscopy. A consecutive paired cohort (n = 292), enrolled after the introduction of a new protocol, additionally received saline-aided US. Diagnostic metrics (accuracy, sensitivity, specificity) and Cohen's kappa were calculated to compare conventional and saline-aided US against histopathological reference standards. Multivariate logistic regression was used to assess clinical parameters affecting diagnostic outcomes. RESULTS: Among 466 recruited patients (mean age 4.83 ± 3.12 years, 276 males), 391 were colonoscopy-positive. The most common pathological type was juvenile intestinal polyp (93.1%); the most frequent location was the rectum (59.3%). Saline-aided US was associated with improved diagnostic performance (accuracy: 81.8%, sensitivity: 81.0%, specificity: 85.0%) compared to conventional US (accuracy: 51.4%, sensitivity: 39.6%). Multivariate analysis identified polyp size and location as factors significantly associated with diagnostic outcome (both p < 0.001). For saline-aided US, smaller polyps (< 10 mm) and those located in the rectum (missed diagnosis rate: 22.8%) were associated with higher rates of missed diagnosis. CONCLUSION: Saline-aided US significantly enhances the detection of colorectal polyps in children, demonstrating superior diagnostic accuracy and sensitivity over conventional US.