<b>Diagnostic Accuracy of Ultrasound in Diagnosing Intussusception Taking Surgical Findings as Gold Standard</b>

Background: Intussusception is the leading cause of intestinal obstruction in children under six years of age, and timely diagnosis is essential to prevent complications. Ultrasonography is widely used as a noninvasive diagnostic tool, yet its diagnostic accuracy compared to surgical findings—the gold standard—remains underexplored in many local populations. Objective: To determine the diagnostic accuracy of ultrasound in detecting intussusception in pediatric patients, using surgical findings as the reference standard. Methods: A cross-sectional validation study was conducted at the Radiology Department of Mardan Medical Complex, Pakistan, from December 2025 to June 2025. Two hundred five children aged 1–12 years with suspected intestinal obstruction were enrolled consecutively. Ultrasound examinations were performed with 3.5 MHz and 8.0 MHz probes, identifying characteristic signs of intussusception. All cases subsequently underwent surgical exploration. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated; stratified analyses explored demographic effects. Statistical significance was assessed using chi-square or Fisher's exact tests. Results: Of 205 patients, 76 (37.1%) were ultrasound-positive, and 62 (30.2%) had surgically confirmed intussusception. Ultrasound demonstrated an overall diagnostic accuracy of 89.3% (95% CI: 84.6–93.1), with sensitivity of 93.5% (95% CI: 84.3–98.2), specificity of 87.4% (95% CI: 81.2–92.1), positive predictive value of 76.3% (95% CI: 65.2–85.3), and negative predictive value of 96.9% (95% CI: 92.2–99.1). Diagnostic accuracy was significantly higher in children aged 1–6 years compared to older children (p=0.024). The presence of both target and pseudokidney signs yielded the highest diagnostic confidence. Conclusion: Ultrasound is a highly accurate, sensitive, and reliable diagnostic modality for pediatric intussusception, especially in younger children, and should be utilized as a first-line imaging technique in suspected cases.