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

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.