title: Radiation dose to breasts from a cardiac computed tomography angiographyscanogram can be reduced by switching tube position.
abstract: OBJECTIVE
  In a computed tomography (CT) examination, scanogram images are used to determine the range of the area to be imaged before scanning. The importance of scanogram image exposure has increased since total examination radiation has decreased due to technological advancements. The purpose of this study was to determine and compare radiation doses delivered to patients while the tube was in anterior-posterior (AP) and posterior-anterior (PA) positions during a CT angiography scanogram.
  
  
  METHODS
  The radiation doses absorbed by the breast tissue of 55 female patients who underwent cardiac dual-source computed tomography (DSCT) angiography were determined using thermoluminescent dosimeters (TLD-100, Harshaw, MA, USA). Four patients were excluded from the study for various reasons.
  
  
  RESULTS
  Radiation doses absorbed by the breasts were significantly lower when the tube position was switched during the scanogram. The absorbed doses, calculated from scanogram exposures, were 520 ± 50 μSv for the AP projection and 410 ± 45 μSv for the PA projection. Total skin doses from the DSCT examinations were 18.9 ± 2.3 mSv.
  
  
  CONCLUSIONS
  We attributed the approximately 20% lower doses to the position of the scanogram tube, which was in the PA position.
authors.affiliation: Department of Biophysics, Faculty of Medicine, Atatürk University, Erzurum, Turkey.
authors.forename: Mustafa Erdem
authors.initials: ME
authors.lastname: Sağsöz
authors.affiliation: Department of Radiology, Faculty of Medicine, Atatürk University, Erzurum, Turkey.
authors.forename: Rüstem Berhan
authors.initials: RB
authors.lastname: Pirimoğlu
mesh_terms: D001940:Breast; D005260:Female; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed
keywords: Multidetector CT radiation dose; X-ray tube position; cardiac CT angiography; scanogram