Department of Physics, University of Trieste, Via Valerio 2, 34127 Trieste, Italy.
Phys Med Biol. 2010 Mar 21;55(6):1643-58. doi: 10.1088/0031-9155/55/6/008. Epub 2010 Feb 24.
Conventional contrast agents utilized in diagnostic radiology are based on x-ray absorption properties; alternative physical principles capable of providing a contrast enhancement in radiographs have never been applied. This study exploits the possibility of using a novel type of contrast media based on x-ray scattering. The contrast agents consist of microbubble echo-enhancing agents, usually applied in ultrasound examinations, which are invisible with conventional x-ray absorption techniques. The experiment was carried out at the medical beamline of the synchrotron radiation laboratory ELETTRA in Trieste, Italy. A flat silicon analyzer crystal typically used for diffraction-enhanced imaging was utilized as a tool for detecting the scattering properties of the contrast agents. In analyzer-based imaging, it is possible to detect the scattering properties of the sample by shifting the analyzer crystal to selected positions of its reflectivity curve. In particular, when the sample consists of a large number of micro-particles an overall effect can be observed. Phantoms containing contrast agents based on microbubbles were imaged at different angular positions of the analyzer crystal. High visibility of the details was demonstrated, and a strong contrast enhancement was measured compared to normal x-ray absorption techniques.
在诊断放射学中使用的传统造影剂基于 X 射线吸收特性；从未应用过能够在射线照片中提供对比度增强的替代物理原理。本研究利用了基于 X 射线散射的新型造影剂的可能性。造影剂由微泡回声增强剂组成，通常应用于超声检查，用常规 X 射线吸收技术是不可见的。该实验在意大利的 Trieste 的同步辐射实验室 ELETTRA 的医用束线上进行。通常用于衍射增强成像的平板硅分析器晶体被用作检测造影剂散射特性的工具。在基于分析器的成像中，可以通过将分析器晶体移动到其反射率曲线的选定位置来检测样品的散射特性。特别是，当样品由大量微粒子组成时，可以观察到整体效果。在分析器晶体的不同角度位置对含有微泡造影剂的幻影进行了成像。与常规 X 射线吸收技术相比，证明了细节的高度可见性，并测量了强烈的对比度增强。
