Basis material decomposition in spectral CT using a semi-empirical, polychromatic adaption of the Beer-Lambert model
Ehn S, Sellerer T, Mechlem K, Fehringer A, Epple M, Herzen J, Pfeiffer F, Noel PB (2017)
Publication Type: Journal article
Publication year: 2017
Journal
Book Volume: 62
Pages Range: N1-N17
Journal Issue: 1
Abstract
Following the development of energy-sensitive photon-counting detectors using high-Z sensor materials, application of spectral x-ray imaging methods to clinical practice comes into reach. However, these detectors require extensive calibration efforts in order to perform spectral imaging tasks like basis material decomposition. In this paper, we report a novel approach to basis material decomposition that utilizes a semi-empirical estimator for the number of photons registered in distinct energy bins in the presence of beam-hardening effects which can be termed as a polychromatic Beer-Lambert model. A maximum-likelihood estimator is applied to the model in order to obtain estimates of the underlying sample composition. Using a Monte-Carlo simulation of a typical clinical CT acquisition, the performance of the proposed estimator was evaluated. The estimator is shown to be unbiased and efficient according to the Cram�r-Rao lower bound. In particular, the estimator is capable of operating with a minimum number of calibration measurements. Good results were obtained after calibration using less than 10 samples of known composition in a two-material attenuation basis. This opens up the possibility for fast re-calibration in the clinical routine which is considered an advantage of the proposed method over other implementations reported in the literature.
Involved external institutions
Germany (DE)How to cite
APA:
Ehn, S., Sellerer, T., Mechlem, K., Fehringer, A., Epple, M., Herzen, J.,... Noel, P.B. (2017). Basis material decomposition in spectral CT using a semi-empirical, polychromatic adaption of the Beer-Lambert model. Physics in Medicine and Biology, 62(1), N1-N17. https://doi.org/10.1088/1361-6560/aa4e5c
MLA:
Ehn, S., et al. "Basis material decomposition in spectral CT using a semi-empirical, polychromatic adaption of the Beer-Lambert model." Physics in Medicine and Biology 62.1 (2017): N1-N17.
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