Department of Biomedical Engineering, Xuanwu Hospital of Capital Medical University, No. 45 Changchun Street, Beijing 100053, PR China.
Eur J Radiol. 2012 Nov;81(11):3577-80. doi: 10.1016/j.ejrad.2011.09.006. Epub 2011 Oct 2.
To assess and compare the radiation dose of DynaCT in phantoms to that of MSCT.
A male Anderson Radiation Therapy 200 phantom with embedded thermoluminescence dosimeters (TLDs) was scanned with DynaCT (Axiom Artis dTA, Siemens Healthcare, Forchheim, Germany) and MSCTs (MSCT1: Lightspeed VCT, GE, Milwaukee, USA; MSCT2: Sensation Cardiac 64, Siemens Healthcare, Erlangen, Germany), respectively. For DynaCT, radiation exposure data with automatic exposure control were obtained from scanning of head, chest and abdomen. For MSCT, scanning protocols for head, chest, and abdomen were examined under conventional exposure conditions. Effective doses were calculated from LiF-TLD measurements according to ICRP103. A Catphan phantom (Phantom Lab, USA) was used to evaluate the spatial resolution and low contrast detectability of DynaCT and MSCT.
The effective doses for DynaCT from head, chest and abdomen scanning were 1.18, 7.32, 7.48 mSv (20 s scan) and 0.85, 6.01, 7.04 mSv (8 s scan); the effective doses for MSCT from head, chest and abdomen scanning were 3.33, 7.62 and 8.42 mSv (MSCT1), and 1.89, 7.52, 8.23 mSv (MSCT2). Significant difference between the organ doses from DynaCT and from MSCT (p<.05) was shown. The spatial resolution of 12 lp/cm was achieved and it was able to recognize a 3mm low contrast object at 0.5% contrast level in DynaCT, which was on the same level as in the MSCT images.
The phantom study indicates that DynaCT applies significantly less dose to patient and achieves similar spatial resolution and low contrast detectability to standard diagnostic MSCT.
评估并比较 DynaCT 与 MSCT 在体模中的辐射剂量。
采用具有嵌入式热释光剂量计（TLDs）的男性安德森放射治疗 200 体模，分别用 DynaCT（Axiom Artis dTA，西门子医疗，德国福伊希特旺）和 MSCT（MSCT1：Lightspeed VCT，GE，美国密尔沃基；MSCT2：Sensation 心脏 64，西门子医疗，德国埃尔兰根）进行扫描。对于 DynaCT，从头部、胸部和腹部的自动曝光控制扫描中获得了辐射暴露数据。对于 MSCT，在常规曝光条件下检查了头部、胸部和腹部的扫描协议。根据 ICRP103 从 LiF-TLD 测量中计算出有效剂量。使用 Catphan 体模（Phantom Lab，美国）评估 DynaCT 和 MSCT 的空间分辨率和低对比度检测能力。
20 秒扫描时，DynaCT 头部、胸部和腹部扫描的有效剂量分别为 1.18、7.32、7.48mSv 和 0.85、6.01、7.04mSv；8 秒扫描时，DynaCT 头部、胸部和腹部扫描的有效剂量分别为 3.33、7.62 和 8.42mSv（MSCT1）和 1.89、7.52、8.23mSv（MSCT2）。DynaCT 和 MSCT 的器官剂量之间存在显著差异（p<.05）。DynaCT 实现了 12lp/cm 的空间分辨率，能够识别 0.5%对比度水平的 3mm 低对比度物体，与 MSCT 图像的水平相同。
该体模研究表明，DynaCT 对患者的辐射剂量明显较低，并且在空间分辨率和低对比度检测能力方面与标准诊断 MSCT 相当。
