Dual-energy computed tomography of the head: a phantom study assessing axial dose distribution, eye lens dose, and image noise level
Dual-energy computed tomography of the head: a phantom study assessing axial dose distribution, eye lens dose, and image noise level
复制标题
头部双能计算机断层扫描：评估轴向剂量分布、眼晶状体剂量和图像噪声水平的模型研究
DOI：
10.1117/12.2216650
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Kichiro Koshida
中科院分区：
文献类型：
--
作者：
Kosuke Matsubara;Hiroki Kawashima;Takashi Hamaguchi;Tadanori Takata;Masanao Kobayashi;Katsuhiro Ichikawa;Kichiro Koshida
本研究的目的是提出一种用于测量双源双能计算机断层扫描（DECT）期间吸收剂量的小型剂量计校准方法，并比较DE和标准单能（SE）头部CT血管造影之间的轴向剂量分布、眼透镜剂量和图像噪声水平。使用第二代双源CT设备和女性头部体模进行了三次DE（100/Sn 140 kVp、80/Sn 140 kVp和140/80 kVp）和一次SE（120 kVp）采集，具有等效的体积CT剂量指数。用辐射光致发光玻璃剂量计测量了眼眶水平的轴向吸收剂量分布和眼透镜的吸收剂量。在眼眶水平的体模的DE复合图像和SE图像中获得CT衰减数。DE采集中眼眶水平和眼透镜中吸收的剂量较低，CT衰减数的标准差略高于SE采集。SE采集的前表面剂量尤其高于DE采集。因此，DE头部CT血管造影术可以以低于标准SE头部CT血管造影术所需的辐射剂量进行，图像噪声水平略有增加。100/Sn 140 kVp采集揭示了最平衡的轴向剂量分布。此外，我们提出的方法是有效的校准小剂量计测量吸收剂量的DECT。
The aim of this study was to propose a calibration method for small dosimeters to measure absorbed doses during dual- source dual-energy computed tomography (DECT) and to compare the axial dose distribution, eye lens dose, and image noise level between DE and standard, single-energy (SE) head CT angiography. Three DE (100/Sn140 kVp 80/Sn140 kVp, and 140/80 kVp) and one SE (120 kVp) acquisitions were performed using a second-generation dual-source CT device and a female head phantom, with an equivalent volumetric CT dose index. The axial absorbed dose distribution at the orbital level and the absorbed doses for the eye lens were measured using radiophotoluminescent glass dosimeters. CT attenuation numbers were obtained in the DE composite images and the SE images of the phantom at the orbital level. The doses absorbed at the orbital level and in the eye lens were lower and standard deviations for the CT attenuation numbers were slightly higher in the DE acquisitions than those in the SE acquisition. The anterior surface dose was especially higher in the SE acquisition than that in the DE acquisitions. Thus, DE head CT angiography can be performed with a radiation dose lower than that required for a standard SE head CT angiography, with a slight increase in the image noise level. The 100/Sn140 kVp acquisition revealed the most balanced axial dose distribution. In addition, our proposed method was effective for calibrating small dosimeters to measure absorbed doses in DECT.