Sonography in patients with suspected acute appendicitis: value in establishing alternative diagnoses.

We reviewed the clinical and sonographic findings in 297 patients who had graded compression sonography for suspected acute appendicitis. The purpose of the study was to determine the accuracy of sonography in detecting other diseases in the 174 patients in this group who proved not to have acute appendicitis. Of the 174 patients without acute appendicitis, 93 patients (53%) were ultimately discharged with a diagnosis of abdominal pain of unknown origin. Of the 81 patients in whom specific diagnoses were established, sonography suggested the correct diagnosis in 57 patients (70%). A broad spectrum of diseases was detected, including: gynecologic diseases (35); visceral diseases, including hollow viscera and diseases of liver, pancreas, or spleen (18); and urinary tract abnormalities (four). This study suggests that sonography is useful in establishing alternative diagnoses in patients undergoing sonography for suspected acute appendicitis.