The Role of MRI in Reducing Paediatric Negative Appendicectomy Rates in Children Under 18 Years Old: A Systematic Review and Meta-Analysis

Abstract

Background: Negative appendicectomies in children can be associated with morbidity. MRI has become a radiation-free alternative to CT to assist in the diagnosis of paediatric appendicitis, particularly when ultrasound is equivocal. A systematic review and meta-analysis were performed to assess the diagnostic accuracy of MRI for paediatric appendicitis and its role in reducing negative appendicectomy rates (NAR). Methods: Searches were performed across PubMed, Embase, Cochrane Library, Scopus, Web of Science, for studies from 1 January 2000 to 31 July 2025. The inclusion criteria were studies of children (<18 years) with suspected appendicitis undergoing MRI. Bivariate random-effects meta-analyses were performed. Meta-regression explored the impact of covariates for example, DWI, contrast use, image reviewer blinding, and magnetic field strength. Results: Twelve studies (n = 3242) met inclusion. Pooled MRI sensitivity was 96.7% (95% CI: 93.4%-98.9%), specificity 97.9% (95% CI: 95.6%-99.3%). MRI NARs ranged from 0.66% to 11.1%, with 3/12 studies reporting NARs <5%. Meta-regression showed non-significant associations between NAR and DWI use (+3.12%, P = .264), MRI contrast use (−5.64%, P = .110), and magnetic field strength (−1.63% per Tesla, P = .361). No significant publication bias was detected (Deeks’ P = .152). Conclusion: MRI demonstrates high diagnostic accuracy and is associated with low negative appendicectomy rates in children. Its use is particularly effective where ultrasound/clinical findings are inconclusive as MRI overcomes ultrasound limitations, poor appendix visualisation, operator-dependence, and inability to exclude alternate diagnoses. Given its radiation-free nature and CT-like diagnostic performance, wider adoption of MRI within paediatric appendicitis pathways may help avoid surgery and reduce exposure to ionising radiation.