Guidelines
Guidelines Summary
European Association of Endoscopic Surgery (EAES) Recommendations
The EAES has made the following recommendations [1]
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Ultrasound is reliable in increasing the likelihood of acute appendicitis but not reliable in excluding the diagnosis.
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CT scanning with IV contrast is superior to ultrasound for appendicitis diagnosis.
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MRI can provide similar diagnostic accuracy to CT.
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Recommend that ultrasound be performed as a first-level diagnostic imaging, although it has lower diagnostic value if confirmation is desired.
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If after ultrasound, the diagnosis is not confirmed or ruled out, CT or MRI should be performed.
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In obese patients, CT or MRI is more accurate than ultrasound and recommended in cases of doubt of diagnosis.
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In pregnant patients, MRI is recommended if diagnosis is in doubt.
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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]
Media Gallery
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Suppurative appendicitis; transverse view, color Doppler ultrasound image. Circumferential colors are observed in the wall of the inflamed appendix (arrows), a strong indicator of acute appendicitis.
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Atypical presentation of appendicitis in a young woman; computed tomography scan. The patient presented with an elevated white blood cell count and right upper quadrant pain. Left, there is pericholecystic fluid and free fluid in the right paracolic gutter, which is caused by retrocecal appendicitis. Right, the appendix, observed in axial section, has an increased diameter and an enhancing thickened wall.
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Appendicitis in a young physician; computed tomography (CT) study. Intravenous (IV) contrast was administered to the patient, who had gram-negative sepsis but no abdominal pain on examination. Left, an inconclusive CT scan after administration of oral contrast but no IV contrast. Right, a repeat CT scan study following administration of IV contrast demonstrates the thickened, enhanced appendiceal wall and periappendiceal changes. The retrocecal location of the appendix may have attenuated abdominal symptoms.
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Acute suppurative appendicitis in a 15-year-old boy; contrast-enhanced, fat-suppressed, T1-weighted, spin-echo coronal magnetic resonance image. A markedly enhanced and thickened inflamed appendix (arrows) with pericecal enhancement due to the extent of inflammation is shown.
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Acute suppurative appendicitis in a 27-year-old woman; scintigraphy study. Pathologic accumulation of technetium-99m human immunoglobulin on the right iliac fossa is observed at 4 hours.
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Periappendiceal abscess; contrast-enhanced, fat-suppressed, T1-weighted, spin-echo coronal magnetic resonance image. Fluid collections (long arrows) and a markedly enhanced pericecal area (short arrows) are shown. b = bladder; c = cecum.
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Normal appendix; barium enema radiographic examination. A complete contrast-filled appendix is observed (arrows), which effectively excludes the diagnosis of appendicitis.
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Normal appendix; computed tomography (CT) scan. A normal appendix, visualized here at the base of the cecum (arrow), is observed in 44-51% of patients. Thin-section CT scans (5-mm collimation or less) are more useful in identifying the appendix. Oral or rectal contrast should be administered. Intravenous contrast is useful in enabling enhancement and edema of the appendiceal wall to be identified.
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Distal appendicitis; computed tomography scan. The appendiceal lumen may be normal proximally (left, arrow), but distension and inflammatory changes are noted distally (right, open arrow).
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Retrocecal appendix; computed tomography scan. Left, the appendix occurs in a retrocecal location in 65% of patients. Right, in this young female, the appendix extends cranially as far as the posterior lobe of the liver. Appendicitis in a patient with a retrocecal appendix may present atypically, with less or poorly localized pain, discomfort on coughing or walking, or flank, rather than right lower quadrant, tenderness.
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Arrowhead sign; computed tomography scan. The presence of this sign indicates contrast outlining the cecum and funneling into the origin of the appendix, with obstruction of the lumen preventing retrograde flow of barium into the distal appendix.
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Acute gangrenous appendicitis with calcified appendicolith; computed tomography (CT) scan. A calcified appendicolith in the lumen of an enlarged inflamed appendix is shown.
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Perforated appendicitis with abscess; computed tomography scan. Note the appendicolith (arrow) and air within the abscess. The terminal ileum lies anterior to the appendiceal abscess, and inflammatory change is noted in its wall, which appears thickened (open arrow).
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Crohn disease in a young woman; computed tomography scan. The patient presented with acute right lower quadrant pain and fever. She had a normal-appearing appendix, but thickening of the wall of the terminal ileum was noted (arrow) in addition to sclerotic changes of both sacroiliac joints, that was consistent with sacroiliitis in association with Crohn disease.
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Severe acute pancreatitis in a young man; computed tomography scans. The patient presented with peripancreatic effusions that resulted in right lower quadrant pain. Fluid had tracked down the right paracolic gutter (left, arrow, coronal section) in addition to the anterior pararenal space (right, axial view).
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Acute suppurative appendicitis; contrast-enhanced, fat-suppressed, T1-weighted, spin-echo axial magnetic resonance image. A markedly enhanced and thickened inflamed appendix (arrows) is shown. a = iliac artery; c = cecum; p = psoas muscle; v = iliac vein.
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Normal appendix; contrast-enhanced, fat-suppressed, T1-weighted, spin-echo coronal magnetic resonance image. Mild enhancement in the unenlarged appendix, ileum (arrowhead), and cecum is shown.
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Normal appendix; longitudinal ultrasonogram. A compressible tubular appendiceal structure with an outer diameter of less than 6 mm (arrows) is shown. A = iliac artery; V = iliac vein.
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Suppurative appendicitis in a 15-year-old boy; longitudinal ultrasonogram. An aperistaltic, noncompressible, blind-ended, fluid-filled, tubular appendiceal structure is shown, and distinct wall layers (arrows) arising from the base of the cecum are observed.
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Phlegmonous appendicitis; oblique-axial ultrasonogram. A pericecal fluid collection, which is walled off by small-bowel loops (arrowheads) is shown, and an appendicolith with an acoustic shadow (arrow) is observed.
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Suppurative appendicitis in a 15-year-old boy; longitudinal view, pathologic specimen. An inflamed appendix with appendicoliths in the lumen (arrow) is demonstrated.
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Gangrenous appendicitis; longitudinal ultrasonogram. A markedly distended appendix (arrows), loss of mucosa and submucosal layers, and prominent echogenic pericecal fat are shown.
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Distended gangrenous appendix; pathologic specimen.
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Perforated appendix; longitudinal ultrasonogram. A defect on the tip (large arrow, right side) of the enlarged appendix (short arrows, left side) is observed. c = cecum.
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Periappendiceal abscess formation; oblique-axial ultrasonogram. A thick-walled, complex, hypoechoic mass adjacent to the cecum (arrows) is shown. The inflamed appendix was not visualized.
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Computed tomography scan reveals an enlarged appendix with thickened walls, which do not fill with colonic contrast agent, lying adjacent to the right psoas muscle.
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