Should MRI Replace Ultrasound as the Primary Imaging Modality in Pediatric Females With Suspected Appendicitis?

Limited sequence, rapid acquisition magnetic resonance imaging (MRI) is an established modality for diagnosing appendicitis, but its ability to assess gynecologic pathology remains unclear. We hypothesize that MRI alone sufficiently evaluates reproductive organs in patients with lower abdominal pain. Female patients (<18yo) undergoing MRI in the Emergency Department between January 2019 and January 2025 were reviewed. Patients were stratified into two groups: MRI alone vs pelvic ultrasound (US) and MRI. 142 patients were included with 93 receiving MRI only and 49 receiving both MRI and US. The MRI mentioned evaluation of pelvic structures in 80% of cases. Ovarian cysts were commented on in 5 patients, of which 4 also had US which added no additional information. No gynecologic pathology was missed on MRI. In this study, we found no gynecologic pathology on US that was not also noted on MRI. These findings suggest that an MRI first diagnostic pathway may be sufficient to rule out gynecologic pathology (Table 1).