The Saudi Journal of Medical Insights

Background: Acute appendicitis is the most common surgical emergency, yet clinical diagnosis remains challenging.
Ultrasound (US) and computed tomography (CT) are primary imaging modalities, but optimal strategies are debated,
particularly in equivocal adult cases.
Objective: To synthesise contemporary evidence comparing the diagnostic accuracy of US and CT for acute appendicitis,
with histopathology as the reference standard.
Methods: Systematic review of PubMed, Scopus, Web of Science, and Cochrane CENTRAL (2021–2026). Included
studies enrolled suspected appendicitis patients, evaluated both modalities, reported diagnostic metrics, and used
histopathology. Quality assessed with QUADAS-2; narrative synthesis performed.
Results: Eight studies comprising 4,608 participants were included. CT demonstrated superior accuracy, with sensitivity
88–99.4% and specificity 71–80%, versus US sensitivity 40–85.7% and specificity 50–62.5%. CT was significantly better
for overweight, obese, and elderly patients (p<0.05). Combining clinical scores with US achieved comparable performance
in selected populations, with negative appendectomy rates as low as 2.9%. CT added limited value for high clinical scores
(≥7) but was beneficial in equivocal cases (scores 4–6). Conclusion: CT offers superior accuracy overall, but a risk
stratified approach is optimal. US with clinical scoring is effective first-line, with CT reserved for inconclusive or complex
cases. Standardised US protocols and operator training are needed to optimise pathways.