title: Acute appendicitis in young adults: low- versus standard-radiation-dose contrast-enhanced abdominal CT for diagnosis.
abstract: OBJECTIVE
  To compare low and standard radiation doses in intravenous contrast material-enhanced abdominal computed tomography (CT) for the diagnosis of acute appendicitis in young adults.
  
  
  METHODS
  The institutional review board approved this retrospective study and waived informed consent. The study included 257 patients (age range, 15-40 years) who underwent CT for suspected appendicitis performed by using a low radiation dose (n = 125) or a standard radiation dose (n = 132). Receiver operating characteristic (ROC) analysis, Fisher exact tests, and Mann-Whitney U tests were used to compare the diagnosis of appendicitis and diagnostic confidence as recorded in prospective CT reports between the two groups.
  
  
  RESULTS
  For 55 low-radiation-dose (median dose-length product, 122 mGy · cm) and 44 standard-dose (median dose-length product, 544 mGy · cm) examinations, one of two abdominal radiologists made primary reports that served as final reports. For the remaining examinations, on-call radiologists with differing levels of experience issued preliminary reports and the two abdominal radiologists then provided final reports. In the primary reports, the low- and standard-dose CT groups did not significantly differ in area under the ROC curve (0.96 vs 0.97, P = .76), sensitivity (90% [38 of 42] vs 89% [47 of 53], P > .99), or specificity (92% [76 of 83] vs 94% [74 of 79], P = .74) in the diagnosis of appendicitis. There was also no significant difference between the two groups in the confidence level when diagnosing (P = .71) or excluding (P = .20) appendicitis in the primary reports. Similar results were observed for the final reports. The two dose groups also did not significantly differ in terms of appendiceal visualization, diagnosis of appendiceal perforation, or sensitivity for alternative diagnoses.
  
  
  CONCLUSIONS
  Low-dose CT may have comparable diagnostic performance to standard-dose CT for the diagnosis of appendicitis in young adults.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Kyoung Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Kyuseok
authors.initials: K
authors.lastname: Kim
authors.forename: Tae Yun
authors.initials: TY
authors.lastname: Kim
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Seung-sik
authors.initials: SS
authors.lastname: Hwang
authors.forename: Ki Jun
authors.initials: KJ
authors.lastname: Song
authors.forename: Heung Sik
authors.initials: HS
authors.lastname: Kang
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Joong Eui
authors.initials: JE
authors.lastname: Rhee
mesh_terms: D000293:Adolescent; D000328:Adult; D001064:Appendicitis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D016015:Logistic Models; D008297:Male; D012372:ROC Curve; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D011860:Radiography, Abdominal / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide