Detectors for the future of X-ray imaging

• Published in: Radiation protection dosimetry Vol. 139; no. 1-3; p. 327
• Main Authors: Aslund, M, Fredenberg, E, Telman, M, Danielsson, M
• Format: Journal Article
• Language: English
• Published: England 01.04.2010
• Subjects: Forecasting; Radiographic Image Enhancement - instrumentation; Radiography - instrumentation; Radiology Information Systems - trends; Technology Assessment, Biomedical; Transducers
• ISSN: 1742-3406
• DOI: 10.1093/rpd/ncq074

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.