Comparison of Imaging Strategies with Conditional Contrast-enhanced CT and Unenhanced MR Imaging in Patients Suspected of Having Appendicitis: A Multicenter Diagnostic Performance Study.

Prospective study of 230 patients with suspected appendicitis. All underwent MRI, and remainder followed clinical pathway with US +/- CT. the results of immediate MRI, conditional MRI after US and conditional CT after US were analyzed. 

Conditonal CT missed appendicitis in 3%, with 8% (10 of 125; 95% CI: 4%, 14%) false-positives.
Conditional MR missed appendicitis in 2% with 10% (13 of 129; 95% CI: 6%, 16%) false-positives.
Immediate MR missed appendicitis in 3% with 6% (seven of 120; 95% CI: 3%, 12%) false-positives.

While no consistent gold standard was applied in this study, the similar results of conditional or staged MRI and CT after inconclusive or negative US are impressive, and support the possibility of using MRI in suspected appendicitis when ionizing radiation from CT is a concern. No information on bmi or detailed demographics were provided to assess for applicability or correlate with results from the paediatric radiology literature.

PICO Analysis:
Population: adult patients with suspected appendicitis
Intervention: unenhanced MRI
Comparison: unenhanced MRI after ultrasound and CT after ultrasound
Outcome: expert consensus (surgeons and radiologists)

Reference: Leeuwenburgh MM et al., Radiology, July 2013, 268(1):135-143.
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