Imaging and diagnosis of acute appendicitis

InvestigationDiagnostic criteriaEvidence
Plain radiographyNoneNo role in diagnosis of acute appendicitis,w6 although in some cases a faecolith may be shown
UltrasonographyAperistaltic and non-compressible structure with diameter >6 mmw8Sensitivity of 86%; specificity of 81%7
Computed tomography scanningAbnormal appendix identified or calcified appendicolith seen in association with periappendiceal inflammation or diameter >6 mmw8Sensitivity of 94% and specificity of 95% in diagnosis of acute appendicitis7
Magnetic resonance imagingNot confirmedRestricted to cases in which radiation and diagnostic difficulties preclude use of other modalities (for example, pregnancy)8 w9