Comparative diagnostic accuracy of ultrasound, CT, and MRI for suspected acute appendicitis in pediatric patients at central child teaching hospital, Baghdad

Background: Acute appendicitis is the leading cause of surgical acute abdomen in children, with misdiagnosis rates of 15-37%. Despite available imaging options ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) few studies have directly compared all three using standardized protocols in the same pediatric population, especially in Middle Eastern settings. This study aims to compare the diagnostic accuracy of US, CT, and MRI for suspected pediatric appendicitis and assess their performance across different age groups. Methods: This prospective observational study was conducted at Central Child Teaching Hospital, Baghdad, Iraq, from January to December 2022, enrolling children aged 2-16 years with suspected acute appendicitis and a Pediatric Appendicitis Score of 3 or higher. Each patient underwent ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) within six hours of presentation. Two independent radiologists, blinded to clinical and other imaging results, interpreted the images. The reference standard was based on surgical findings confirmed by histopathology or 30-day clinical follow-up. Results: Of 324 patients (mean age 9.8 years; 57.4% male), 198 cases (61.1%) were confirmed as acute appendicitis. MRI showed the highest diagnostic accuracy (93.5%) compared to CT (91.4%) and US (80.6%). Sensitivity was greatest for MRI (94.4%), followed by CT (92.4%) and US (78.3%), while specificity was 92.1% for MRI, 89.7% for CT, and 84.1% for US. The area under the ROC curve was 0.933 for MRI, 0.911 for CT, and 0.812 for US. MRI outperformed US significantly (p