Accuracy of ultrasound in the diagnosis of acute appendicitis compared with the surgeon's clinical impression.

Objective: To compare the accuracy of the surgeon's clinical diagnosis of acute appendicitis with that of an ultrasonographic examination of the abdomen. Design: Prospective trial. Setting: US Naval Hospital, San Diego, Calif. Patients: One hundred ten patients admitted to the hospital with suspected appendicitis from May 1990 to June 1992. Intervention: Symptoms and signs for each patient were recorded, along with the surgeon's clinical impression of immediate surgery or observation. The patient then underwent an ultrasound examination performed by a staff radiologist. On the basis of the ultrasound findings the patient was placed into one of three categories: appendicitis, normal examination results, or other conditions. Patients with an ultrasound-based diagnosis of appendicitis proceeded to the operation, regardless of the surgeon's clinical impression. Those with other conditions diagnosed with ultrasonography were treated as was appropriate for the condition. Results: The ultrasound-derived diagnosis of appendicitis had a sensitivity of 85.5%, a specificity of 84.4%, a positive predictive value of 88.3%, a negative predictive value of 80.1%, and an overall accuracy of 85.0%. The surgeon's clinical impression at the time of admission had a sensitivity of 62.9%, a specificity of 82.2%, a positive predictive value of 82.9%, a negative predictive value of 61.7%, and an overall accuracy of 71.2%. Conclusion: The overall accuracy of ultrasonography in the diagnosis of appendicitis was statistically superior to that of the surgeon's clinical impression ( P (Arch Surg. 1993;128:1039-1046)