title: Female breast radiation exposure during thorax multidetector computed tomography and the effectiveness of bismuth breast shield to reduce breast radiation dose.
abstract: OBJECTIVE
  The purpose of our study was to determine the breast radiation dose when performing routine thoracic multidetector computed tomography (MDCT). We also evaluated dose reduction and the effect on image quality of using a bismuth breast shield when performing thoracic MDCT.
  
  
  METHODS
  The dose reduction achievable by shielding the adult (18 years or older) female breasts was studied in 50 women who underwent routine thoracic MDCT. All examinations were performed with a 16-MDCT scanner (Sensation Cardiac 16; Siemens Medical Solutions). To compare the shielded/unshielded breast dose, the examination was performed with (right breast) and without (left breast) breast shielding in all patients. With this technique, the superficial breast doses were calculated. To determine the average glandular breast radiation dose, we imaged an anthropomorphic dosimetric phantom into which calibrated dosimeters were placed to measure the dose to breast. The phantom was imaged using the same protocol. Radiation doses to the breasts with and without the breast shielding were measured and compared using the Student t test.
  
  
  RESULTS
  In the qualitative evaluation of the MDCT scans, all were considered to be of diagnostic quality. We did not see any differences in quality between the shielded and unshielded lung. The mean radiation doses to the breasts with the shield and to those without the shield were 8.6 +/- 2.33 versus 14.46 +/- 3.94 mGy, respectively. The breast shield enabled a 40.53% decrease in radiation dose to the breast. The difference between the dose received by the breasts with and that received by the breasts without bismuth shielding was significant, with a P value of less than 0.001.
  
  
  CONCLUSIONS
  Bismuth in-plane shielding for routine thoracic MDCT decreased radiation dose to the breast without qualitative changes in image quality. The other radiosensitive superficial organs (eg, testes and thyroid gland) specifically must be protected with shielding.
authors.affiliation: Department of Radiology, Cerrahpasa Medical Faculty, Istanbul University, Turkey. drmhyilmaz@yahoo.com
authors.forename: Mehmet Halit
authors.initials: MH
authors.lastname: Yilmaz
authors.forename: Sait
authors.initials: S
authors.lastname: Albayram
authors.forename: Doğan
authors.initials: D
authors.lastname: Yaşar
authors.forename: Harun
authors.initials: H
authors.lastname: Ozer
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Adaletli
authors.forename: Doğan
authors.initials: D
authors.lastname: Selçuk
authors.forename: Canan
authors.initials: C
authors.lastname: Akman
authors.forename: Ayça
authors.initials: A
authors.lastname: Altuğ
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001729:Bismuth; D001940:Breast / Q000528:radiation effects*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008875:Middle Aged; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation*; D013902:Radiography, Thoracic; D014057:Tomography, X-Ray Computed
chemical_list: D001729:Bismuth