title: Systematic Evaluation of Radiation Dose Reduction in CT Studies of Body Packers: Accuracy Down to Submillisievert Levels.
abstract: OBJECTIVE
  The objective of this study was to systematically evaluate the accuracy of abdominal CT performed at different radiation dose levels for the detection of body packs in human cadavers, in comparison with the accuracy of abdominal radiography.
  
  
  METHODS
  In this study, differing numbers of body packs (range, 0-20) were placed in the alimentary tract of human cadavers and then underwent imaging with abdominal radiography and with CT performed at different radiation dose levels (ranging from the standard abdominal CT dose to the technical minimum dose). Depiction of body packs on abdominal radiographs and on each CT scan was assessed by two independent blinded radiologists, and the accuracy of detection of body packs was calculated. The radiation dose associated with abdominal radiography was measured, and the effective radiation dose associated with CT was estimated.
  
  
  RESULTS
  The mean (± SD) effective radiation dose for abdominal radiography was 1.4 ± 0.3 mSv, whereas the mean effective dose of CT ranged from 0.1 to 9.6 mSv. Interobserver agreement for body pack detection was moderate (κ = 0.51) for abdominal radiography and good (κ = 0.72-0.85) for CT. In a per-body pack analysis, abdominal radiography depicted 42% of the body packs with a sensitivity of 71% and a specificity of 100%. When performed at radiation dose levels of 0.6 mSv or greater, CT correctly detected all body packs. In per-person analysis, the sensitivity and specificity of CT for the correct detection of at least one body pack per cadaver was 100% for all radiation dose levels.
  
  
  CONCLUSIONS
  CT performed at a dose of 0.6 mSv can be used for the detection of body packs. With a sensitivity and specificity of 100%, CT is superior to abdominal radiography in terms of reliability, associated radiation dose, and accuracy of detection.
authors: 1 Institute of Forensic Medicine, University of Zurich, Switzerland, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors: Patrick J
authors: PJ
authors: Laberke
authors: 2 Institute of Legal Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland.
authors: Simon
authors: S
authors: Blum
authors: 3 Division of Radiology and Nuclear Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland.
authors: Stephan
authors: S
authors: Waelti
authors: 3 Division of Radiology and Nuclear Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland.
authors: Jürgen
authors: J
authors: Fornaro
authors: 2 Institute of Legal Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland.
authors: Roland
authors: R
authors: Hausmann
authors: 4 Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors: Hatem
authors: H
authors: Alkadhi
authors: 3 Division of Radiology and Nuclear Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland.|4 Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors: Sebastian
authors: S
authors: Leschka
mesh_terms: D002102:Cadaver; D005547:Foreign Bodies / Q000000981:diagnostic imaging*; D006801:Humans; D011829:Radiation Dosage; D011860:Radiography, Abdominal / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: abdominal radiography; body packer; low-dose CT; radiation dose