title: To shield or not to shield: application of bismuth breast shields.
abstract: OBJECTIVE
  The purposes of this essay are to describe the effects of bismuth breast shielding on radiation exposure of the breast and posterior chest wall and to present arguments for and against the use of breast shields.
  
  
  CONCLUSIONS
  Breast tissue may receive substantial radiation doses during CT examinations. Bismuth shields effectively reduce breast exposure at the expense of increased noise and artifacts. Because bismuth shields reduce radiation transmission in all directions, posterior-to-anterior irradiation results in wasted exposure of posterior tissues. Similar breast radiation reductions can be achieved without shielding by globally reducing tube current. In general, more advanced methods of reducing exposure, including dose modulation and iterative reconstruction techniques, are superior if available.
authors: Department of Radiology, University of Southern California Keck School of Medicine, LAC+USC Medical Center, 1200 N State St, Los Angeles, CA 90033, USA. Colletti@usc.edu
authors: Patrick M
authors: PM
authors: Colletti
authors: Orlando A
authors: OA
authors: Micheli
authors: Kai H
authors: KH
authors: Lee
mesh_terms: D001729:Bismuth; D001940:Breast; D062485:Breath Holding; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011835:Radiation Protection / Q000295:instrumentation*; D011874:Radiometry; D014057:Tomography, X-Ray Computed / Q000009:adverse effects / Q000295:instrumentation*
chemical_list: D001729:Bismuth