Determination of shielding requirements for mammography.
Shielding requirements for mammography when considerations are to be given to attenuation by compression paddle, breast tissue, grid and image receptor (intervening materials) has been investigated. By matching of the attenuation and hardening properties, comparisons are made between shielding afforded by breast tissue materials (water, Lucite and 50%-50% adipose-glandular tissue) and some materials considered for shielding diagnostic x-ray beams, namely lead, steel and gypsum wallboard. Results show that significant differences exist between the thickness required to produce equal attenuation and that required to produce equal hardening of a given incident beam. While attenuation equivalent thickness produces equal exposure, it does not produce equal hardening. For shielding purposes, equivalence in exposure reduction without equivalence in penetrating power of an emerging beam does not amount to equivalence in shielding affordable by two different materials. Presented are models and results of sample calculations of additional shielding requirements apart from that provided by intervening materials. The shielding requirements for the integrated beam emerging from intervening materials are different from those for the integrated beam emerging from materials (lead/steel/gypsum wallboard) with attenuation equivalent thicknesses of these intervening materials.
Okunade
Akintunde Akangbe
AA
Department of Physics, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria. aokunade@oauife.edu.ng
Ademoroti
Olalekan Albert
OA
D001822:Body Burden; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design / Q000379:methods; D006801:Humans; D008327:Mammography / Q000009:adverse effects* / Q000295:instrumentation* / Q000379:methods; D008954:Models, Biological; D017785:Photons; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods; D011874:Radiometry / Q000379:methods*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors