title: Implementation of a split-bolus single-pass CT protocol at a UK major trauma centre to reduce excess radiation dose in trauma pan-CT.
abstract: OBJECTIVE
  To quantify the dose reduction and ensure that the use of a split-bolus protocol provided sufficient vascular enhancement.
  
  
  METHODS
  Between 1 January 2014 and 31 May 2014, both split bolus and traditional two-phase scans were performed on a single CT scanner (SOMATOM Definition AS+, Siemens Healthcare) using a two-pump injector (Medrad Stellant). Both protocols used Siemens' proprietary tube current and tube voltage modulation techniques (CARE dose and CARE kV). The protocols were compared retrospectively to assess the dose-length product (DLP), aortic radiodensity at the level of the coeliac axis and radiodensity of the portal vein.
  
  
  RESULTS
  There were 151 trauma CT examinations during this period. Seventy-eight used the split-bolus protocol. Seventy-one had traditional two-phase imaging. One patient was excluded as they were under the age of 18 years. The radiodensity measurements for the portal vein were significantly higher (p<0.001) in the split-bolus protocol. The mean aortic enhancement in both protocols exceeded 250 HU, although the traditional two-phase protocol gave greater arterial enhancement (p<0.001) than the split-bolus protocol. The split-bolus protocol had a significantly lower (p<0.001) DLP with 43.5% reduction in the mean DLP compared to the traditional protocol.
  
  
  CONCLUSIONS
  Split-bolus CT imaging offers significant dose reduction for this relatively young population while retaining both arterial and venous enhancement.
authors.affiliation: Imaging Department, Royal Stoke University Hospital, Newcastle Road, Stoke-on-Trent, ST4 6QG, UK. Electronic address: Vincent.leung@uhns.nhs.uk.
authors.forename: V
authors.initials: V
authors.lastname: Leung
authors.affiliation: Imaging Department, Royal Stoke University Hospital, Newcastle Road, Stoke-on-Trent, ST4 6QG, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sastry
authors.affiliation: Imaging Department, Royal Stoke University Hospital, Newcastle Road, Stoke-on-Trent, ST4 6QG, UK.
authors.forename: T D
authors.initials: TD
authors.lastname: Woo
authors.affiliation: Imaging Department, Royal Stoke University Hospital, Newcastle Road, Stoke-on-Trent, ST4 6QG, UK.
authors.forename: H R
authors.initials: HR
authors.lastname: Jones
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014193:Trauma Centers; D006113:United Kingdom
chemical_list: D003287:Contrast Media