title: Coronary calcium scoring with MDCT: the radiation dose to the breast and the effectiveness of bismuth breast shield.
abstract: OBJECTIVE
  The purpose of our study was to determine the breast radiation dose during coronary calcium scoring with multidetector computerized tomography (MDCT). We also evaluated the degree of dose reduction by using a bismuth breast shield when performing coronary calcium scoring with MDCT.
  
  
  METHODS
  The dose reduction achievable by shielding the adult (35 years or older) female breasts was studied in 25 women who underwent coronary calcium scoring with MDCT. All examinations were performed with a 16-MDCT scanner. To compare the shielded versus unshielded breast dose, the examinations were 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 the 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's t-test.
  
  
  RESULTS
  The mean radiation doses with and without the breast shield were 5.71+/-1.1 mGy versus 9.08+/-1.5 mGy, respectively. The breast shield provided a 37.12% decrease in radiation dose to the breast with shielding. The difference between the dose received by the breasts with and without bismuth shielding was significant, with a p-value of less than 0.001.
  
  
  CONCLUSIONS
  The high radiation during MDCT greatly exceeds the recommended doses and should not be underestimated. Bismuth in plane shielding for coronary calcium scoring with MDCT decreased the radiation dose to the breast. We recommend routine use of breast shields in female patients undergoing calcium scoring with MDCT.
authors.affiliation: Istanbul University, Cerrahpasa Medical Faculty, Department of Radiology, Istanbul, Turkey. drmhyilmaz@yahoo.com
authors.forename: Mehmet Halit
authors.initials: MH
authors.lastname: Yilmaz
authors.forename: Doğan
authors.initials: D
authors.lastname: Yaşar
authors.forename: Sait
authors.initials: S
authors.lastname: Albayram
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Adaletli
authors.forename: Harun
authors.initials: H
authors.lastname: Ozer
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ozbayrak
authors.forename: Ismail
authors.initials: I
authors.lastname: Mihmanli
authors.forename: Canan
authors.initials: C
authors.lastname: Akman
mesh_terms: D000328:Adult; D001729:Bismuth; D001822:Body Burden; D001940:Breast; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009928:Organ Specificity; D011482:Protective Devices; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods; D011874:Radiometry / Q000379:methods*; D011877:Radionuclide Imaging; D012062:Relative Biological Effectiveness; D018570:Risk Assessment / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D001729:Bismuth