Elizabeth Lazarus MD, Presenter: Nothing to Disclose

William W. Mayo-Smith MD, Abstract Co-Author: Nothing to Disclose

Martha Beretta Mainiero MD, Abstract Co-Author: Nothing to Disclose

To compare the diagnostic yield of Computed Tomography (CT) with ultrasound in pregnant women presenting to the emergency room with non-traumatic abdominal pain.

We performed a search of our computer database to identify all pregnant women who underwent a CT scan for the symptom of non-traumatic abdominal pain presenting to the emergency room between 9/2000 and 2/2004. CT findings were tabulated from the report and compared with the results of ultrasounds performed within 48 hours. Imaging findings were correlated with medical and operative follow up in all patients.

52 pregnant women (13% in the first trimester, 44 % second trimester, and 44% third trimester) had CT for the evaluation of abdominal pain. CT findings were normal (n=21), pregnancy related hydronephrosis (n=13), appendicitis (n=6), urinary tract calculi (n=4), cholelithiasis (n=2), pyelonephritis (n=2), small bowel obstruction (n=1), diaphragmatic hernia (n=1), and cecal bascule (n=1). Average dose delivered to the fetus was 13.2 milligray. 38 (79%) of the 52 patients had an ultrasound within 48 hours of the CT scan; 33 (87%) performed prior to the CT scan, and 4 (13%) post CT. Ultrasound findings were normal (n=30), hydronephrosis (n=4), cholelithiasis (n=3), and possible appendicitis (n=1). In patients with normal ultrasound, CT diagnosed appendicitis (n=3), urinary tract calculus (n=2), small bowel obstruction (n=1), diaphragmatic hernia (n=1), pyelonephritis (n=1), and cecal bascule (n=1). In patients with normal CT, ultrasound diagnosed gallstones (n=2). Follow-up appendectomy was performed in 8 patients, 7 of whom had acute appendicitis. CT diagnosed appendicitis pre-operatively in 6 of 7 (86%) of these patients. Three separate patients with a normal ultrasound and a definitive diagnosis established on CT underwent cystoscopy for retrieval of a ureteral calculus, repair of a diaphragmatic hernia and lysis of adhesions for small bowel obstruction.

CT is useful in evaluating abdominal pain in pregnant women and established clinically important diagnoses in 30% of patients who had normal ultrasounds.

Lazarus, E, Mayo-Smith, W, Mainiero, M, Abdominal Pain in Pregnant Women: Computed Tomography or Ultrasound?.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4407220.html