Department of Cardiovascular Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
AJR Am J Roentgenol. 2011 Sep;197(3):W508-13. doi: 10.2214/AJR.10.5798.
Contrast medium causes side effects such as contrast-induced nephropathy, and the dose of contrast medium is a risk factor in their occurrence. To reduce doses of contrast medium, we developed an angiographic system with high definition and high sensitivity and reviewed its effectiveness. The system entails synchrotron radiation, which is characterized by high photon density and straightness of beam that together result in high resolution, and a high-gain avalanche rushing amorphous photoconductor receiver, which is 100 times more sensitive than conventional charge-coupled device cameras.
Diluted contrast medium was administered, and angiography of rat hindlimbs was performed with synchrotron radiation and the high-gain photoconductor receiver. The difference in gray-scale value between the background and contrast medium was calculated. Images were evaluated by counting of arteries.
The difference in contrast at low levels was detected with the high-gain photoconductor receiver but not with the charge-coupled device camera. The photon density of synchrotron radiation with the high-gain photoconductor receiver was one-fifth that with the charge-coupled device camera. The high-gain photoconductor receiver had approximately 5 times the sensitivity of the charge-coupled device camera.
Use of the synchrotron radiation and high-gain photoconductor receiver makes it possible to perform angiography with an extremely low concentration of contrast medium.
造影剂会引起副作用,如对比剂肾病,造影剂的剂量是其发生的一个危险因素。为了减少造影剂的剂量,我们开发了一种高清高敏的血管造影系统,并对其效果进行了评价。该系统采用同步加速器辐射,其特点是光子密度高,光束直,因此分辨率高,以及具有 100 倍于传统电荷耦合器件(CCD)相机的高增益雪崩式无定型光导接收器。
用同步加速器辐射和高增益光导接收器对大鼠后肢进行稀释造影剂血管造影,计算背景与造影剂之间的灰度值差异。通过动脉计数评估图像。
用高增益光导接收器检测到低水平的对比度差异,但 CCD 相机则无法检测到。用高增益光导接收器的同步加速器辐射的光子密度是 CCD 相机的五分之一。高增益光导接收器的灵敏度约为 CCD 相机的 5 倍。
使用同步加速器辐射和高增益光导接收器可以用极低浓度的造影剂进行血管造影。