MRI Adoption in Pediatric Appendicitis-Trends and Outcomes.

Background and objectives: Magnetic resonance imaging (MRI) protocols have been implemented to diagnose appendicitis without exposure to ionizing radiation. Our objective was to describe MRI adoption trends and evaluate the association of MRI adoption with appendicitis complications.

Methods: We performed a retrospective cohort study of children aged less than 19 years old with appendicitis presenting to 46 pediatric emergency departments between 2010 to 2023. The exposure was presentation at an MRI-adopting hospital, defined as a hospital using MRI more often (> 50%) than computed tomography for patients requiring cross-sectional imaging for appendicitis, determined annually. The primary outcome was complicated appendicitis, based on diagnosis codes for perforation, sepsis, bowel resection, or abscess drainage. Secondary outcomes included intensive care unit admission and hospital length of stay. Logistic regression models with a random intercept for hospital were used to identify the association of MRI adoption and complications.

Results: Among 155 884 children with appendicitis, 19 232 presented to MRI-adopting hospitals (12.3%). MRI adoption increased 16.2% per year (95% CI, 8.0-25.0), from 3.0% in 2010 to 18.2% in 2023. MRI adoption was associated with lower odds of any complication (adjusted odds ratio [aOR] 0.79, 95% CI, 0.74-0.84). Appendiceal perforation (aOR 0.77, 95% CI, 0.72-0.82) and abscess drainage (aOR 0.84, 95% CI, 0.73-0.96) occurred less frequently in MRI-adopting hospitals. Intensive care unit admissions were less common at MRI-adopting hospitals (1.1% vs 1.6%; P < .001).

Conclusions: Children's hospitals have slowly adopted MRI for appendicitis, but most still primarily rely on computed tomography. Our finding that MRI adoption is associated with a lower risk of complicated appendicitis warrants further investigation.