Diagnostic Accuracy of Point-of-Care Ultrasound versus CT for Acute Appendicitis in the Emergency Department

Abstract

Background: Acute appendicitis is the most common surgical cause of acute abdominal pain. Contrast-enhanced computed tomography (CT) is highly  accurate  but exposes predominantly  young patients  to  ionizing radiation and may delay disposition. Point-of-care ultrasound (POCUS), performed by the treating emergency or radiology physician at the bedside. Objective: To determine the diagnostic accuracy of POCUS compared with contrast-enhanced CT, and to assess the effect of operator experience and body mass index (BMI) on performance.
Patients and methods: A prospective single-center diagnostic-accuracy cohort study was conducted at Al-Hussein teaching hospital in Nasiriyah, from 1 June 2023 through 1 December 2025. Adults aged 18 years or older with acute right-lower-quadrant pain underwent a structured index POCUS examination  followed  by  reference-standard  contrast-enhanced  CT. POCUS operators were blinded to CT results, and CT readers were blinded to POCUS findings. The primary outcomes were sensitivity, specificity, positive and negative likelihood ratios, and the area under the receiver operating characteristic curve (AUC).
Results: Of 364 patients assessed, 298 formed the analytic cohort; 121 (40.6%)  had  CT-confirmed  acute  appendicitis.  POCUS  achieved  a sensitivity  of  84.3%  (95%  confidence  interval  [CI]  76.6–90.3%)  and specificity of 89.3% (95% CI 83.7–93.4%), with positive likelihood ratio 7.87 and negative likelihood ratio 0.18 and AUC 0.86 (95% CI 0.81–0.91). Conclusions: POCUS  achieved  good  diagnostic  accuracy  for  acute appendicitis and may serve as an effective first-line triage test, particularly when  performed  by  credentialed  operators  in  non-obese  patients, potentially reducing CT utilization in selected adults.