The Solid State X-ray Image Intensifier (SSXII) in Single Photon Counting (SPC) mode.
The new Solid State X-Ray Image Intensifier (SSXII) has the unique ability to operate in single photon counting (SPC) mode, with improved resolution, as well as in traditional energy integrating (EI) mode. The SSXII utilizes an electron-multiplying CCD (EMCCD), with an effective pixel size of 32μm, which enables variable signal amplification (up to a factor of 2000) prior to digital readout, providing very high-sensitivity capabilities. The presampled MTF was measured in both imaging modes using the standard angulated-slit method. A measured detector entrance exposure of 24μR per frame was used to provide approximately 0.8 interaction events per pixel in the 10μm-wide slit area. For demonstration purposes, a simple thresholding technique was used to localize events in SPC mode and a number of such frames were summed to provide an image with the same total exposure used for acquiring the EI image. The MTF for SPC mode, using a threshold level of 15% of the maximum 12-bit signal and 95% of the expected events, and for EI mode (in parentheses) was 0.67 (0.20), 0.37 (0.07), 0.20 (0.03), and 0.11 (0.01) at 2.5, 5, 7.5, and 10 cycles/mm, respectively. Increasing the threshold level resulted in a corresponding increase in the measured SPC MTF and a lower number of detected events, indicating a tradeoff between resolution and count efficiency is required. The SSXII in SPC mode was shown to provide substantial improvements in resolution relative to traditional EI mode, which should benefit applications that have demanding spatial resolution requirements, such as mammography.
University at Buffalo (State University of New York), Toshiba Stroke Research Center, 3435 Main St., Buffalo, NY USA 14214.
Andrew
A
Kuhls-Gilcrist
Amit
A
Jain
Daniel R
DR
Bednarek
Stephen
S
Rudin
Proc SPIE Int Soc Opt Eng. 2006 Dec 2;6142(61421R):
21297904
Med Phys. 1997 Dec;24(12):1819-33
9434965
IEEE Trans Med Imaging. 1992;11(1):34-9
18218354
Med Phys. 2009 Apr;36(4):1330-9
19472640
Proc SPIE Int Soc Opt Eng. 2008;6913:69130K
18836568
Med Phys. 2008 Jan;35(1):301-9
18293585
Proc SPIE Int Soc Opt Eng. 2010 Mar 23;7622(76224W):76224W-76244W9
21170177
Med Phys. 2010 Feb;37(2):724-35
20229882
Proc SPIE Int Soc Opt Eng. 2007;6510(1):65101C
21654934
Proc SPIE Int Soc Opt Eng. 2009 Jan 1;7258:7258171-72581710
19763251