title: Is Oral Contrast Necessary for Multidetector Computed Tomography Imaging of Patients With Acute Abdominal Pain?
abstract: OBJECTIVE
  The purpose of our study was to validate the hypothesis that eliminating the use of oral contrast for multidetector computed tomography (MDCT) would not affect the detection of acute abdominal abnormalities in emergency room patients.
  
  
  METHODS
  We conducted a retrospective study to assess the effect of discontinuing oral contrast use for MDCT scans of the abdomen and pelvis for patients presenting with acute abdominal pain and body mass index (BMI) >25. Patients with BMI <25 continued to receive oral contrast. The medical records were reviewed to determine the rate of repeat imaging within 7 days from the initial CT scan, as well as delayed or missed diagnoses related to the absence of oral contrast. The study was approved by the research ethics board at our institution.
  
  
  RESULTS
  A total of 1378 patients had an MDCT examination of the abdomen and pelvis between November 1, 2012, and October 31, 2013. 375 patients met the inclusion criteria (174 males and 201 females; mean age 57 years; range 18-97 years). Seven of 375 (1.9%) patients had a repeat CT examination with oral contrast within 7 days. Of these 7 patients, none had a change in the course of their management due to the utilization of oral contrast. No delayed or missed diagnoses related to the absence of oral contrast were identified.
  
  
  CONCLUSIONS
  Omitting oral contrast for imaging patients with BMI >25 presenting with acute abdominal pain resulted in no delayed or missed diagnoses, in our retrospective study. The benefits of prompt imaging diagnosis outweigh the unlikely need for repeat imaging.
authors.affiliation: Division of Emergency/Trauma Radiology, Department of Radiology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Alabousi
authors.affiliation: Division of Emergency/Trauma Radiology, Department of Radiology, McMaster University, Hamilton, Ontario, Canada. Electronic address: patlas@hhsc.ca.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Patlas
authors.affiliation: Department of Surgery, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Niv
authors.initials: N
authors.lastname: Sne
authors.affiliation: Department of Radiology, Winthrop-University Hospital, Mineola, New York, USA.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Katz
mesh_terms: D000006:Abdomen, Acute / Q000000981:diagnostic imaging* / Q000209:etiology*; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D009864:Ontario; D010388:Pelvis / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: Abdominal pain; Multidetector computed tomography; Oral contrast