Masuda Takanori, Funama Yoshinori, Nakaura Takeshi, Sato Tomoyasu, Urayama Kotaro, Kiguchi Masao, Oku Takayuki, Yoshida Masato, Arao Shinichi, Ono Atsushi, Hiratsuka Junichi, Awai Kazuo
Department of Radiological Technology, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, 288, Matsushima, Kurashiki, 701-0193, Kurashiki-city, Okayama, Japan.
Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo, 860-8556, Kumamoto, Japan.
Phys Eng Sci Med. 2023 Mar;46(1):289-293. doi: 10.1007/s13246-023-01217-8. Epub 2023 Jan 12.
To investigate optimizing the use of different beam shaping filters (viz. small, medium and large) when using different tube voltages during the newborn chest computed tomography (CT) on a GE Lightspeed VCT scanner.
We used pediatric anthropomorphic phantoms with a 64 detector-row CT scanner while scanning the chest. A real-time skin dosimeter (RD - 1000; Trek Corporation, Kanagawa, Japan) was positioned into the phantom center of the body, the surface of the body back, and the right and left mammary glands. We performed and compared six scan protocols using small, medium, and large beam shaping filters at 80 and 120 kVp protocols.
There were no significant differences in the image noise for the chest scan among the different beam shaping filters. By using the large beam shaping filter at 80 kVp, it was possible to reduce the exposure dose by 5% in comparison with the small beam shaping filter, and by 10% in comparison with the medium beam shaping filter. By using the large beam shaping filter at 120 kVp, it was possible to reduce the exposure dose by 15% in comparison with the small beam shaping filter and by 20% in comparison with the medium beam shaping filter (p < 0.01).
The large beam shaping filter had the most dose reduction effect during newborn chest CT on a GE Lightspeed VCT scanner. The additional copper filtration being present in the large bowtie filter of the GE Lightspeed CT scanner when using different tube voltages is more effective in reducing radiation exposure in children.
研究在GE光速VCT扫描仪上对新生儿进行胸部计算机断层扫描（CT）时，使用不同管电压时优化不同光束整形滤波器（即小、中、大）的使用情况。
我们在使用64排探测器CT扫描仪扫描胸部时使用了儿科人体模型。将实时皮肤剂量仪（RD - 1000；日本神奈川县的Trek公司）放置在人体模型的身体中心、身体背部表面以及左右乳腺处。我们在80 kVp和120 kVp扫描协议下，使用小、中、大光束整形滤波器执行并比较了六种扫描协议。
不同光束整形滤波器之间胸部扫描的图像噪声没有显著差异。在80 kVp时使用大光束整形滤波器，与小光束整形滤波器相比，可将照射剂量降低5%，与中光束整形滤波器相比可降低10%。在120 kVp时使用大光束整形滤波器，与小光束整形滤波器相比，可将照射剂量降低15%，与中光束整形滤波器相比可降低20%（p < 0.01）。
在GE光速VCT扫描仪上对新生儿进行胸部CT扫描时，大光束整形滤波器的剂量降低效果最为显著。当使用不同管电压时，GE光速CT扫描仪大蝴蝶结滤波器中额外的铜过滤在减少儿童辐射暴露方面更有效。
