Assessment of Ultrasound Accuracy in Diagnosing Appendicitis at Federal Medical Centre Umuahia, Abia State

Acute appendicitis is among the most common surgical emergencies presenting to Nigerian emergency departments, and ultrasound is the first-line diagnostic imaging modality in resource-limited settings where computed tomography is unavailable or cost-prohibitive. The diagnostic accuracy of ultrasound for appendicitis in South East Nigerian medical centres has not been systematically evaluated against surgical and histopathological findings. This study assesses the sensitivity, specificity, and overall diagnostic accuracy of ultrasound in diagnosing acute appendicitis at Federal Medical Centre Umuahia, Abia State. A retrospective correlative design is employed, reviewing 180 ultrasound examination reports in patients subsequently managed for suspected appendicitis from 2020 to 2023. Ultrasound findings are compared against operative and histopathological reference standards to compute sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy. Receiver operating characteristic curve analysis is performed in SPSS. Literature from South East Nigerian emergency imaging settings identifies sonographic visualisation of the appendix as technically challenging in obese patients and in the presence of overlying bowel gas, reducing sensitivity in approximately 30 to 40 percent of examinations. The ACR Appropriateness Criteria for right lower quadrant pain provide the clinical imaging reference. Findings are expected to demonstrate sensitivity of 70 to 80 percent, below the published performance of CT, with implications for institutional referral protocols. Recommendations address graded compression ultrasound training and criteria for CT escalation when ultrasound is non-diagnostic at FMC Umuahia. Keywords: ultrasound, appendicitis, diagnostic accuracy, Federal Medical Centre Umuahia, Abia State.