New high-speed scanning technique for computed radiography

Publisher Website
Google Scholar
Abstract
The natural luminescence decay time of storage phosphors limits the scan speed of today's flying-spot scanners, since this 'afterglow' emission degrades the MTF along the fast-scan direction. Higher scan speeds can also decrease the total amount of signal captured at each point, that is, the read-out depth. One may reduce these problems by scanning entire lines at once, rather than points. However, this can create other problems related to stimulation and collection efficiency, system gain, sharpness, and noise. We have developed a new scanning engine containing a linear, laser-diode-based stimulation source and a light collection system with specially designed optics and multiple, linear, asymmetric CCDs. The stimulation/collection systems are housed in a compact, movable read head that scans quickly over a stationary image plate (IP). We evaluated this so-called 'ScanHead' with conventional powder (IPs) and with new CsBr:Eu2+ needle-based IPs.We also compared it to a conventional flying-spot scanner. Image quality results differed depending on plate type. DQE values for conventional powder IPs in the prototype scanner were comparable to today's state-of-the-art commercial systems (DQE(0)~0.25-0-27). DQE values for needle IPs were significantly better than those for powder IPs (DQE(0) ~0.58-0-60) and comparable to those quoted for flat-panel DR systems based on CsI:Tl.

This publication has 0 references indexed in Scilit: