Aslund M, Fredenberg E, Telman M, Danielsson M
Sectra Mamea AB, Smidesvägen 2, 171 41 Solna, Sweden.
Radiat Prot Dosimetry. 2010 Apr-May;139(1-3):327-33. doi: 10.1093/rpd/ncq074. Epub 2010 Mar 5.
In recent decades, developments in detectors for X-ray imaging have improved dose efficiency. This has been accomplished with for example, structured scintillators such as columnar CsI, or with direct detectors where the X rays are converted to electric charge carriers in a semiconductor. Scattered radiation remains a major noise source, and fairly inefficient anti-scatter grids are still a gold standard. Hence, any future development should include improved scatter rejection. In recent years, photon-counting detectors have generated significant interest by several companies as well as academic research groups. This method eliminates electronic noise, which is an advantage in low-dose applications. Moreover, energy-sensitive photon-counting detectors allow for further improvements by optimising the signal-to-quantum-noise ratio, anatomical background subtraction or quantitative analysis of object constituents. This paper reviews state-of-the-art photon-counting detectors, scatter control and their application in diagnostic X-ray medical imaging. In particular, spectral imaging with photon-counting detectors, pitfalls such as charge sharing and high rates and various proposals for mitigation are discussed.
近几十年来，用于X射线成像的探测器技术取得了进展，提高了剂量效率。例如，通过使用柱状碘化铯等结构化闪烁体，或通过直接探测器（其中X射线在半导体中转换为电荷载流子）实现了这一点。散射辐射仍然是主要的噪声源，而效率相当低的反散射网格仍是金标准。因此，未来的任何发展都应包括改进散射抑制。近年来，光子计数探测器引起了几家公司以及学术研究团体的极大兴趣。这种方法消除了电子噪声，这在低剂量应用中是一个优势。此外，能量敏感型光子计数探测器可通过优化信号与量子噪声比、解剖背景扣除或物体成分的定量分析来实现进一步改进。本文综述了光子计数探测器的最新技术、散射控制及其在诊断X射线医学成像中的应用。特别讨论了光子计数探测器的光谱成像、电荷共享和高计数率等陷阱以及各种缓解建议。
