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I.
Imaging in Acute Abdominal Pain
II. Authors
C. Craig Blackmore, MD, MPH
Department of Radiology
Tina Chang, MD
Department of Medicine
Gregory Avey, MD
Department of Radiology
Harborview Medical Center
University of Washington
325 Ninth Avenue, Box 359728
Seattle WA 98104
206-731-3561
fax: 206-731-8560
III. Issues
Given the broad range of diagnoses that may cause acute abdominal pain, several
important diseases are examined in other chapters in this book. Guidelines regarding the
imaging of ureteral calculi, ectopic pregnancy, hepatobiliary disease, and vascular disease
can be found in their respective chapters. Other frequent etiologies of acute abdominal
pain are discussed in this chapter as individual entities.
1.
Appendicitis :
A. What is the accuracy of imaging for diagnosing acute
appendicitis in adults?
B. What is the accuracy of imaging for diagnosing acute appendicitis
in children?
2.
Small Bowel Obstruction
A. What is the accuracy of imaging for diagnosing small bowel
obstruction?
B. What is the accuracy of CT for detecting small bowel
ischemia?
3.
Diverticulitis
A. What is the accuracy of imaging for acute colonic diverticulitis?
B. What is the accuracy of CT in predicting the success
of conservative management in patients with
suspected acute colonic diverticulitis?
IV. Key points
-
Computed tomography examination of adult patients has high sensitivity and
specificity for acute appendicitis and is superior to graded compression
ultrasound. [Moderate Evidence]
-
In pediatric patients, ultrasound has high sensitivity and specificity for acute
appendicitis and is preferred over CT due to absence of ionizing radiation.
[Moderate Evidence]
-
CT has high negative predictive value for ischemic bowel in subjects with small
bowel obstruction [Moderate Evidence]
-
CT has high accuracy for detection of colonic diverticulitis [Moderate Evidence],
but the effect on patient management and outcome has not been established
[Limited Evidence].
X. Discussion of Issues
1A. What is the accuracy of imaging for diagnosing acute
appendicitis in adults?
Summary
Computed tomography examination of adult patients has high sensitivity and specificity
for acute appendicitis and is superior to graded compression ultrasound. [Moderate
Evidence]
It is unclear if the increased use of CT has decreased the rate of negative appendectomies.
[Limited Evidence]
1B. What is the accuracy of imaging for diagnosing acute appendicitis
in children?
Summary
Graded compression ultrasound is highly sensitive and specific in detecting acute
appendicitis in the pediatric population. [Moderate Evidence]
A protocol of graded compression ultrasound followed by CT examination in equivocal
cases has a higher sensitivity, but lower specificity than ultrasound alone in detecting
acute appendicitis in the pediatric population because of increased false positives.
[Moderate Evidence]
There is conflicting evidence regarding the effect of imaging on the rate of negative
appendectomy . [Limited Evidence]
2A. What is the accuracy of imaging for diagnosing small bowel
obstruction?
Summary
CT and ultrasound have higher sensitivity and specificity than conventional plain film
abdominal imaging for diagnosing small bowel obstruction. [Moderate Evidence]
Computerized tomography has a higher sensitivity in the detection of small bowel
obstruction than ultrasound examination. [Limited evidence]
2B. What is the accuracy of CT in detecting small bowel ischemia?
Summary
CT examination of patients with suspected small bowel is highly sensitive and specific in
detecting small bowel ischemia. [Moderate Evidence]
3A. What is the accuracy of imaging for acute colonic diverticulitis?
Summary
Computerized tomography demonstrates a higher sensitivity and specificity in detecting
acute colonic diverticulitis than graded compression ultrasound. [Moderate Evidence]
The data regarding the relative sensitivity and specificity of CT compared with contrast
enema radiography is in conflict. [Limited Data]
3B. What is the accuracy of CT in predicting the success of conservative
management in patients with suspected acute colonic diverticulitis?
Summary
Patients judged to have severe diverticular disease by computed tomography are more
likely to require initial surgical management and to secondarily experience relapse,
persistence, sigmoid stenosis, and fistula or abscess formation. [Limited Evidence]
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