The effectiveness of bismuth breast shielding with protocol optimization in CT scans of the thorax

Background: Numerous techniques had been proposed to reduce radiation exposure in computed tomography (CT) including the use of radiation shielding. Objective: This study aims to evaluate efficacy of using a bismuth breast shield and optimized scanning parameter to reduce breast absorbed doses from...

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Bibliographic Details
Main Authors: Abdul Karim, Muhammad Khalis, Rahim, N. A., Matsubara, K., Hashim, Suad, Abu Mhareb, Mohammad Hasan, Musa, Yahaya
Format: Article
Language:English
Published: IOS Press 2018
Online Access:http://psasir.upm.edu.my/id/eprint/74161/
http://psasir.upm.edu.my/id/eprint/74161/1/The%20effectiveness%20of%20bismuth%20breast%20shielding%20with%20protocol%20optimization%20in%20CT%20scans%20of%20the%20thorax.pdf
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Summary:Background: Numerous techniques had been proposed to reduce radiation exposure in computed tomography (CT) including the use of radiation shielding. Objective: This study aims to evaluate efficacy of using a bismuth breast shield and optimized scanning parameter to reduce breast absorbed doses from CT thorax examination. Methods: Five protocols comprising the standard CT thorax clinical protocol (CP1) and four modified protocols (CP2 to CP5) were applied in anthropomorphic phantom scans. The phantom was configured as a female by placing a breast component on the chest. The breast component was divided into four quadrants, where 2 thermoluminescence dosimeters (TLD-100) were inserted into each quadrant to measure the absorbed dose. The bismuth shield was placed over the breast component during CP4 and CP5 scans. Results: The pattern of absorbed doses in each breast and quadrant were approximately the same for all protocols, where the 4th quadrant > 3rd quadrant > 2nd quadrant > 1st quadrant. The mean absorbed dose value in CP3 was reduced to almost 34% of CP1's mean absorbed dose. It was reduced even lower to 15% of CP1's mean absorbed dose when the breast shield was used in CP5. Conclusion: This study showed that CT radiation exposure on the breast could be reduced by using a bismuth shield and low tube potential protocol without compromising the image quality.