title: Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone.
abstract: OBJECTIVE
  To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT.
  
  
  METHODS
  One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDI(vol)), dose-length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared.
  
  
  RESULTS
  In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDI(vol) (8.3 vs. 12.4 mGy; -33%) and DLP (594 vs. 909 mGy cm; -35%) in the entire autokV group were significantly lower than in the group with fixed 120 kV (p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level.
  
  
  CONCLUSIONS
  Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level.
  
  
  CONCLUSIONS
  • Automated kV selection in thoraco-abdominal trauma CT results in significant dose savings • Most patients benefit from a 100-kV protocol with relevant DLP reduction • Constantly good image quality is ensured • Image quality benefits from higher kV when arms are positioned downward.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Frellesen
authors.forename: Wenzel
authors.initials: W
authors.lastname: Stock
authors.forename: J Matthias
authors.initials: JM
authors.lastname: Kerl
authors.forename: Thomas
authors.initials: T
authors.lastname: Lehnert
authors.forename: Julian L
authors.initials: JL
authors.lastname: Wichmann
authors.forename: Christoph
authors.initials: C
authors.lastname: Nau
authors.forename: Emanuel
authors.initials: E
authors.lastname: Geiger
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wutzler
authors.forename: Martin
authors.initials: M
authors.lastname: Beeres
authors.forename: Boris
authors.initials: B
authors.lastname: Schulz
authors.forename: Boris
authors.initials: B
authors.lastname: Bodelle
authors.forename: Hanns
authors.initials: H
authors.lastname: Ackermann
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
authors.forename: Ralf W
authors.initials: RW
authors.lastname: Bauer
mesh_terms: D000007:Abdominal Injuries / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000295:instrumentation*; D009104:Multiple Trauma / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013898:Thoracic Injuries / Q000000981:diagnostic imaging*; D055815:Young Adult