Official guideline from the American College of Emergency Physicians.
summary by Eric Steinberg, DO
In patients with suspected acute appendicitis, use clinical findings (ie, signs and symptoms) to risk-stratify patients and guide decisions about further testing (eg, no further testing, laboratory tests, and/or imaging studies), and management (eg, discharge, observation, and/or surgical consultation).
In adult patients undergoing a computed tomography (CT) scan for suspected appendicitis, perform abdominal and pelvic computed tomography scan with or without contrast (intravenous [IV], oral, or rectal). The addition of intravenous and oral contrast may increase the sensitivity of the computed tomography scan for the diagnosis of appendicitis.
In children, use ultrasound to confirm acute appendicitis but not to definitively exclude acute appendicitis.
In children, use an abdominal and pelvic computed tomography (CT) to confirm or exclude acute appendicitis.