Feasibility of using a kinestatic charge detector for dual-energy chest radiography

Article type: Research Article

Authors: Schmithorst, Vincent J. | Endorf, Robert J. | Kulatunga, Sunil | Spelic, David C. | DiBianca, Frank A. | Rodriguez, Carlos | Zeman, Herbert D. | Zhu, Zeping | Giakos, George C.

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

Abstract: The feasibility of using a Kinestatic Charge Detector (KCD) for dual-energy chest radiography is investigated. A KCD is a gas ionization chamber used with a scanning slot-beam geometry. Dual-energy imaging involves acquisition of two images with different mean photon energies which can then be reconstructed using a suitable algorithm to form images of two basis materials, such as bone and soft-tissue. With a KCD, dual-energy imaging 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. We have investigated the feasibility of a dual-energy KCD using computer simulations for both dual-kVp and split-detector systems. The theoretically determined contrast resolutions for aluminum and plexiglas were found to be sufficient for clinical diagnosis; however, electronic noise was found to be a major limiting factor. The dual-kVp method was found to yield significant improvements over the split-detector method at high material thicknesses.

Journal: Journal of X-Ray Science and Technology, vol. 12, no. 1, pp. 1-11, 2004