title: Diagnosing acute appendicitis using a nonoral contrast CT protocol in patients with a BMI of less than 25.
abstract: The objective of this study was to compare the accuracy for the diagnosis of appendicitis in patients presenting to the emergency department (ED) with acute, nontraumatic abdominal pain and a body mass index (BMI) of less than 25 before and after the implementation of a nonoral contrast computed tomography (CT) protocol with intravenous contrast. The IRB approved this HIPAA-compliant retrospective study; informed consent was waived. This study included 736 adult patients with a BMI of less than 25 presenting to our ED with acute, nontraumatic abdominal pain over two distinct 6-month time periods. An oral and intravenous contrast-enhanced protocol was utilized in the first cohort (group A), and an intravenous contrast-enhanced protocol without oral contrast was utilized in the second cohort (group B). Three abdominal fellowship-trained readers retrospectively reviewed all CT studies and electronic medical records, including surgical/pathology reports that served as reference standards. Group A consisted of 359 patients; 41 patients had surgically proven appendicitis. The sensitivity and specificity of the readers for diagnosing appendicitis in group A ranged from 95.2-100 and 98.1-99.5 %, respectively. Group B consisted of 372 patients; 39 had surgically proven appendicitis. The sensitivity and specificity of the readers in group B ranged from 92.0-100 and 98.6-100 %, respectively. There were no statistically significant differences in sensitivity or specificity for CT scans performed in groups A and B. In patients with a BMI of less than 25, an intravenous contrast-enhanced CT protocol without oral contrast demonstrates similar accuracy to an intravenous contrast-enhanced protocol with oral contrast for diagnosing acute appendicitis.
authors.affiliation: Department of Radiology, Boston University Medical Center, 820 Harrison Ave, FGH Building, 3rd Floor, Boston, MA, 02118, USA.
authors.forename: Vijay
authors.initials: V
authors.lastname: Ramalingam
authors.affiliation: Department of Radiology, Boston University Medical Center, 820 Harrison Ave, FGH Building, 3rd Floor, Boston, MA, 02118, USA. David.Bates@bmc.org.
authors.forename: David D B
authors.initials: DD
authors.lastname: Bates
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Buch
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Uyeda
authors.affiliation: Department of Radiology, McMaster University, Hamilton, ON, Canada.
authors.forename: Kathy M
authors.initials: KM
authors.lastname: Zhao
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Lindsey A
authors.initials: LA
authors.lastname: Storer
authors.affiliation: Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Marisa B
authors.initials: MB
authors.lastname: Roberts
authors.affiliation: Department of Radiology, Boston University Medical Center, 820 Harrison Ave, FGH Building, 3rd Floor, Boston, MA, 02118, USA.
authors.forename: Christina A
authors.initials: CA
authors.lastname: Lebedis
authors.affiliation: Department of Radiology, Boston University Medical Center, 820 Harrison Ave, FGH Building, 3rd Floor, Boston, MA, 02118, USA.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Soto
authors.affiliation: Department of Radiology, Boston University Medical Center, 820 Harrison Ave, FGH Building, 3rd Floor, Boston, MA, 02118, USA.
authors.forename: Stephan W
authors.initials: SW
authors.lastname: Anderson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001064:Appendicitis / Q000000981:diagnostic imaging*; D015992:Body Mass Index; D003287:Contrast Media; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: Acute abdomen; Appendicitis; CT; Emergency radiology; Oral contrast; Protocols