Clinical-radiological scoring system for enhanced diagnosis of acute appendicitis

Abstract

Introduction: Acute appendicitis is the most common surgical condition in industrialized countries. However, diagnosis in borderline cases is often cumbersome and requires follow-up examinations, and/or a Computed Tomography examination. Therefore, our aim was to develop a combined clinical and sonographic score to enhance prediction of acute appendicitis.

Patients and methods: The modified Alvarado score and various established sonographic criteria were investigated in 132 patients with suspected acute appendicitis. Two models were computed accounting for missing values. After analysis of sensitivity and specificity for the modified Alvarado score, logistic regression analysis was performed to identify significantly contributing sonographic features.

Results: The threshold of the logistic regression analysis of the two models resulted in the formula: modified Alvarado score+axial Appendix diameter [mm]. When the Appendix diameter is>8mm, 1 point/mm is added, while for a diameter<8mm, 1 point/mm is subtracted. The cut-off value is≥13 for acute appendicitis with a sensitivity 91.4% and a specificity of 100%, compared to a sensitivity of 90% and a specificity of 84.4% for the modified Alvarado score in our cohort.

Conclusion: The established modified Alvarado score for diagnosis of acute Appendicitis can be improved by adding the axial diameter of the Appendix in a sonographic examination.

Keywords: Appendicitis; Appendix diameter; Clinical-radiological scoring system; Modified alvarado score; Ultrasound; Vermix.