Ultrasound's Use in Diagnosing Acute Appendicitis

However, its benefits are only fully appreciated within the context of clinical algorithms. The joint evaluation of score results and a clinical evaluation may deliver similar accuracy. The study was published in the World Journal of Surgery (2001;25:578-584).

The study involved 2,209 patients admitted for suspicion of aA, who underwent ultrasound by a surgeon. Researchers evaluated the diagnostic and procedural performance of clinical decision-making, ultrasound, two scoring systems (Ohmann and Eskelinen scores), and clinical algorithms taking account of clinical and either ultrasound findings or score results. The results of each modality were correlated with final diagnoses obtained by laparotomy in 696 patients, of whom 540 were found to have aA.

Ultrasound showed the highest specificity (97%, compared to 93% for the Ohmann and Eskelinen score and 94% for clinical evaluation and algorithms). Ultrasound also showed the lowest overall rate of false-positive findings (negative laparotomy rate of 7.6%). The scores were accurate in showing the diagnosis of aA to be false but otherwise were not superior to ultrasound. The best overall diagnostic and procedural results were obtained with the algorithms that combined the results of either ultrasound or the Ohmann score with clinical evaluation. This combination also produced the most favorable numbers of negative laparotomies, potential perforations, and missed cases of aA.

Although ultrasound is the standard diagnostic modality for patients suspected of aA and yields results superior to scoring systems and clinical evaluation, its benefits can be only appreciated by ultrasonographically trained surgeons within the context of clinical algorithms. The researchers concluded that similar accuracy could be provided by a joint evaluation of score results and clinical evaluation.