Affiliations: Physics Department, University of Cincinnati, OH,
USA | Biomedical Engineering Department, University of
Tennessee, Memphis, TN, USA | Department of Biomedical Engineering, College of
Engineering, University of Akron, OH, USA
Note: [] Corresponding author: Vincent J. Schmithorst, Ph.D., Imaging
Research Center, Children's Hospital Medical Center, Mail Location 5031,
Cincinnati, OH 45229, USA. Tel.: +1 513 636 3922; Fax: +1 513 6363754; E-mail:
Vince.Schmithorst@cchmc.org
Abstract: The Kinestatic Charge Detector (KCD) technique of projection
radiography shows promise when used for dual-energy imaging, which may be
performed either by taking two separate exposures at different kVp settings
(the dual-kVp method) or by taking a single exposure with the KCD segmented
into a front and back region (the split-detector method), as the higher energy
photons will be preferentially absorbed in the back region. Using computer simulations, we have optimized the dual-energy
performance of a segmented KCD using the split-detector method for chest
radiography. Theoretical optimization of imaging parameters and determination
of contrast resolution were performed by minimizing pixel variances of the
basis materials. The expected contrast resolution of the aluminum and plexiglas
basis material images was found to be acceptable for purposes of clinical
diagnosis. A detector medium of krypton produced better results than xenon at
the same density, and the optimal kVp setting was in the range of 120–150 kVp.
Preliminary dual-energy images were taken with a small field-of-view
split-detector imaging KCD system. The experimentally obtained aluminum and
plexiglas basis material pixel variances agree with the theoretical
results.
