ABSTRACT
Breast shielding can reduce dose to the female breast, a radiosensitive organ receiving significant radiation during computed tomography (CT) chest examinations, particularly in cardiac CT, where Electrocardiogram dose modulation currently precludes the use of radial dose modulation to reduce breast dose. However, breast shields may produce artefacts affecting interpretation of coronary arteries. This study explores the dose savings and the effect of breast shields on image quality with torso and CT dose index body phantoms and an organ dose calculator. Change in dose calculated: 53-63 % (female breast), 82-85 % (lung), 79-84 % (oesophagus) and 76-80 % (effective dose) with larger dose reductions at lower kVp. Image quality is preserved when breast shields are placed after the scout no closer than 10 mm from the skin. Therefore, breast shields can be used in cardiac CT to reduce breast dose without compromising image quality. Revised conversion factors for dose length product to effective dose are suggested for cardiac CT without and with breast shields.
Subject(s)
Breast/radiation effects , Phantoms, Imaging , Radiation Protection/instrumentation , Radiographic Image Interpretation, Computer-Assisted , Radiography, Thoracic/standards , Tomography, X-Ray Computed , Female , Humans , Relative Biological EffectivenessABSTRACT
A 47-year-old man with a past history of splenectomy was referred for biopsy of a liver lesion. A subsequent (99m)technetium heat-damaged red cell scan helped make the diagnosis of splenosis and averted a biopsy procedure.