DIAGNOSTIC ACCURACY OF ULTRASOUND IN THE DIAGNOSIS OF ACUTE APPENDICITIS IN PATIENTS WITH RIGHT ILIAC FOSSA PAIN TAKING PER-OPERATIVE FINDINGS AS GOLD STANDARD

Abstract

Introduction: Acute appendicitis (AA) is a leading cause of acute abdomen requiring emergency surgery. Prompt diagnosis is vital to prevent perforation, related morbidity and mortality. Ultrasonography (US) offers a non-invasive, cost-effective, and radiation-free diagnostic option, especially in low-resource settings. This study assessed the diagnostic accuracy of ultrasound in detecting AA, taking per-operative findings as the gold standard.

Methodology: This cross-sectional validation study was conducted at Ayub Teaching Hospital, Abbottabad, and Lady Reading Hospital, Peshawar (January 2024 to February 2025). A total of 139 patients aged ≥ 18 years with right iliac fossa pain and clinical suspicion of AA were included through consecutive sampling. Abdominal ultrasound was performed by consultant radiologists using defined criteria (appendiceal diameter > 6 mm, non-compressibility, peri-appendiceal fluid, and ± appendicolith). Data were analyzed in SPSS v.27 to calculate sensitivity, specificity, predictive values, and overall accuracy.

Results: Ultrasound correctly identified appendicitis in 87 patients and excluded it in 31 patients (p < 0.001). Sensitivity was 85.3%, specificity 83.8%, PPV 93.6%, NPV 67.4%, and overall accuracy 84.9%. Diagnostic performance was comparable across genders, with slightly higher PPV among females. For Alvarado < 7, ultrasound achieved 100% sensitivity and NPV, while PPV approached 99% in Alvarado ≥ 7 cases.

Conclusion: Ultrasound has a high accuracy for diagnosing AA, reliably excluding the disease in low-risk and confirming it in high-risk patients. It remains a safe, accessible, and cost-effective first-line imaging modality, supporting its integration into diagnostic algorithms in resource-limited healthcare settings.