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Proceedings Paper

Noise and signal detection in digital x-ray detectors using the spatial definition of SNR
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Paper Abstract

For task specific evaluation of imaging systems it is necessary to obtain detailed descriptions of their noise and deterministic properties. In the past we have developed an experimental and theoretical methodology to estimate the deterministic detector response of a digital x-ray imaging system, also known as the H matrix. In this paper we have developed the experimental methodology for the evaluation of the quantum and electronic noise of digital radiographic detectors using the covariance matrix K. Using the H matrix we calculated the transfer of a simulated coronary artery constriction through an imaging system's detector, and with the covariance matrix we calculated the detectability (or Signal-to-Noise Ratio) and the detection probability. The eigenvalues and eigenvectors of the covariance matrix were presented and the electronic and quantum noise were analyzed. We found that the exposure at which the electronic noise equals the quantum noise at 90 kVp was 0.2 μR. We compared the ideal Hotelling observer with the Fourier definition of the SNR for a toroidal stenosis on a cylindrical vessel. Because of the shift-invariance and cyclo-stationarity assumptions, the Fourier SNR overestimates the performance of imaging systems. This methodology can be used for task specific evaluation and optimization of a digital x-ray imaging system.

Paper Details

Date Published: 14 March 2009
PDF: 10 pages
Proc. SPIE 7258, Medical Imaging 2009: Physics of Medical Imaging, 725819 (14 March 2009); doi: 10.1117/12.813843
Show Author Affiliations
Iacovos S. Kyprianou, CDRH, U.S. Food and Drug Administration (United States)
Aldo Badano, CDRH, U.S. Food and Drug Administration (United States)
Subok Park, CDRH, U.S. Food and Drug Administration (United States)
Haimo Liu, CDRH, U.S. Food and Drug Administration (United States)
Kyle J. Myers, CDRH, U.S. Food and Drug Administration (United States)


Published in SPIE Proceedings Vol. 7258:
Medical Imaging 2009: Physics of Medical Imaging
Ehsan Samei; Jiang Hsieh, Editor(s)

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