Breast glanduler dose and effectiveness of in-plane bishmut breast shield in routine pediatric female chest CT examination

Abstract

Background: The aim of our study is to calculate the radiation dose to which the breast is exposed in pediatric female undergoing routine thoracic multislice computed tomography (MSCT) and to investigate the effectiveness of bismuth shielding in reducing this dose.

Materials and Methods: Twenty patients who were referred to the radiology department for routine thorax MSCT between January 2012 and April 2012 were included in the study. All CT scans were performed with a 128-channel MSCT device (Siemens Somatom Definition AS Siemens AG, Medical Solutions ,Computed Tomography, Forcheim, Germany). A Thermolucent dosimeter (TLD) (3x3x1mm; Harshaw Lif TLD-100; Saint-Gobain Industrial Ceramics, Solon, Ohio) was placed on both breast skins of the patients to measure the radiation dose. A in-plane bismuth breast shield was placed on the right breast, and the left breast was chosen as the unshielded side. Radiation doses in the shielded and unshielded breast were calculated and compared using the Paired-t test.

Results: The mean radiation doses were calculated as 7.0075 mSv and 9.0730 mSv for the shielded right breast and the unshielded left breast, respectively. It was found that in-plane bismuth breast shielding could lower the radiation dose to the right breast by 22.76 %.The difference between the radiation doses of the shielded side of the breast and the unshieldeded side was found to be significant (p<0.001). No deterioration was detected in the image quality of the lung parenchyma on the side where bismuth shielding was placed.

Conclusions: In-plane bismuth shielding significantly reduces the radiation dose of the breast in pediatric female undergoing routine thoracic MSCT examination without impairing the image quality.