Appendicitis Imaging Guidelines

Updated: Jul 03, 2017
  • Author: Lutfi Incesu, MD; Chief Editor: Eugene C Lin, MD  more...
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Guidelines

Guidelines Summary

European Association of Endoscopic Surgery (EAES) Recommendations

The EAES has made the following recommendations [1]

  • Ultrasound is reliable in increasing the likelihood of acute appendicitis but not reliable in excluding the diagnosis.
  • CT scanning with IV contrast is superior to ultrasound for appendicitis diagnosis.
  • MRI can provide similar diagnostic accuracy to CT.
  • Recommend that ultrasound be performed as a first-level diagnostic imaging, although it has lower diagnostic value if confirmation is desired.
  • If after ultrasound, the diagnosis is not confirmed or ruled out, CT or MRI should be performed.
  • In obese patients, CT or MRI is more accurate than ultrasound and recommended in cases of doubt of diagnosis.
  • In pregnant patients, MRI is recommended if diagnosis is in doubt.
  • In children, MRI is recommended if daignosis is in doubt.

 

American College of Radiology

According to the American College of Radiology (ACR), computed tomography is the most accurate imaging study for evaluating suspected acute appendicitis and alternative etiologies of right lower quadrant pain. In children, ultrasound is the preferred initial examination, because it is nearly as accurate as CT for the diagnosis of acute appendicitis in this population without use of ionizing radiation. In pregnant women, ultrasound is preferred initially, with MRI as a second imaging examination in inconclusive cases. [2, 3]

Appropriateness criteria have been published by the ACR for right lower quadrant pain suggestive of appendicitis. In the appropriateness criteria, ratings of 7 to 9 are considered "usually appropriate." Computed tomography of the abdomen and pelvis with intravenous contrast is rated 8, and CT of the abdomen and pelvis without contrast is rated 7. [2, 3]

Ratings of 4 to 6 indicate that studies "may be appropriate." Right lower quadrant ultrasound with graded compression is rated 6, and abdominal radiographs (for excluding free air or obstruction) are rated 5. Magnetic resonance imaging is rated 4. Ratings of 1 to 3 indicate that studies "are usually not appropriate." Barium enema and technetium-99m white cell scanning are rated 3. [2, 3]