title: Computed tomography overexposure as a consequence of extended scan length.
abstract: BACKGROUND
  This study aimed to raise awareness around the increased effective dose as scan length chosen is increased from standard protocol
  
  
  METHODS
  The Monte Carlo-based software CT-Expo (G. Stamm (Medizinische Hochschule Hannover, Hannover, Germany) and H.D. Nagel (SASCRAD, Buchholz, Germany)) was used to simulate the effective dose increase as the scanned region of the standard protocol increased.
  
  
  RESULTS
  The results of this study show that for scans with a high computed tomography dose index (CTDI)vol the patient could be exposed to an extra 1 mSv within 6 cm of overscan. Protocols that investigated large scan areas may not see a significant relative dose reduction because of the use of a lower CTDIvol ; however, radiation exposure should be kept as low as reasonably achievable.
  
  
  CONCLUSIONS
  There is significant dose optimisation potential when strictly adhering to appropriate scan lengths within each imaging protocol wherever possible.
authors.affiliation: Department of Medical Physics, Austin Health, Heidelberg, Victoria, Australia.|School of Medical Sciences, RMIT, Bundoora, Victoria, Australia.
authors.forename: Mohamed Khaldoun
authors.identifier: http://orcid.org/0000-0001-8029-9951
authors.initials: MK
authors.lastname: Badawy
authors.affiliation: Department of Radiology, Austin Health, Heidelberg, Victoria, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Galea
authors.affiliation: Department of Medical Physics, Austin Health, Heidelberg, Victoria, Australia.
authors.forename: Kam Shan
authors.initials: KS
authors.lastname: Mong
authors.affiliation: Department of Medical Physics, Austin Health, Heidelberg, Victoria, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: U
mesh_terms: D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis*; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods*; D018570:Risk Assessment / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*
keywords: CT dose optimisation; CT dose reduction; computed X-ray tomography; radiation dose; radiography