The impact of breast shielding on radiation dose during computed tomography procedures.

To quantify and compare breast radiation dose across CT protocols using shielding and automatic tube current modulation (ATCM) in single- and dual-energy scanning modes. Surface breast dose was measured using a calibrated pencil ionization chamber placed in a female anthropomorphic phantom. Scans were performed on a 128-slice CT system across multiple anatomical regions using manual mA, ATCM, lead shielding, and single- and dual-energy modes. In single-energy abdominal CT, shielding reduced measured surface breast dose by 12.2%, and ATCM provided an additional 38.2% reduction. Dual-energy CT resulted in higher measured surface breast doses than single-energy, but shielding reduced dose by approximately 62%. The greatest reductions were observed in head and neck (63.7%) and facial bone scans (89.5%). Lead shielding and ATCM effectively reduced surface breast radiation dose, particularly in regions dominated by scatter. Dual-energy imaging increased dose, while combining shielding with ATCM provided the greatest reduction.