Magnetic Resonance Imaging for Pediatric Appendicitis: Utilization Patterns to Guide Future Imaging Strategies

Ultrasound (US) is currently the primary modality for assessing acute appendicitis in children. However, as rapid abdominal magnetic resonance imaging (MRI) protocols become more readily available, using MRI as a first-line modality in certain patients may decrease the need for additional studies and reduce time to diagnosis.

This study evaluates imaging utilization patterns for suspected appendicitis at a large pediatric emergency department and identifies clinical scenarios where MRI may serve as a more efficient first-line imaging modality.

We retrospectively analyzed 5856 pediatric and young adult patients who underwent US, MRI, or both for suspected appendicitis (2016-2023), focusing on imaging utilization, demographics, and examination timing.

US was used as the primary modality in 86% of cases, with 22% of these patients requiring subsequent MRI. 7% of patients underwent MRI first. Time from imaging order to completion was significantly longer for the US + MRI group (217.72 min) compared to US-only (101.82 min) or MRI-only (120.75 min) (p < 0.001). Age, weight, and female sex correlated with increased US examination duration (p < 0.001), whereas MRI times remained consistent. MRI use increased from day (20.3%) to evening (23.4%) to night (29.5%), while US use declined but remained the dominant modality (p < 0.001).

Nearly a quarter of patients undergoing US for appendicitis evaluation ultimately proceed to MRI, resulting in diagnostic delays. MRI may be underutilized as a first-line modality in this subset of patients.