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Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Marquette University

2015

Computed tomography

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Quantifying Cross-Scatter Contamination In Biplane Fluoroscopy Motion Analysis Systems, Janelle A. Cross, Ben Mchenry, Taly Gilat-Schmidt Oct 2015

Quantifying Cross-Scatter Contamination In Biplane Fluoroscopy Motion Analysis Systems, Janelle A. Cross, Ben Mchenry, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Biplane fluoroscopy is used for dynamic in vivo three-dimensional motion analysis of various joints of the body. Cross-scatter between the two fluoroscopy systems may limit tracking accuracy. This study measured the magnitude and effects of cross-scatter in biplane fluoroscopic images. Four cylindrical phantoms of 4-, 6-, 8-, and 10-in. diameter were imaged at varying kVp levels to determine the cross-scatter fraction and contrast-to-noise ratio (CNR). Monte Carlo simulations quantified the effect of the gantry angle on the cross-scatter fraction. A cadaver foot with implanted beads was also imaged. The effect of cross-scatter on marker-based tracking accuracy was investigated. Results demonstrated …


The Effects Of Extending The Spectral Information Acquired By A Photon-Counting Detector For Spectral Ct, Taly Gilat Schmidt, Kevin C. Zimmerman, Emil Y. Sidky Jan 2015

The Effects Of Extending The Spectral Information Acquired By A Photon-Counting Detector For Spectral Ct, Taly Gilat Schmidt, Kevin C. Zimmerman, Emil Y. Sidky

Biomedical Engineering Faculty Research and Publications

Photon-counting x-ray detectors with pulse-height analysis provide spectral information that may improve material decomposition and contrast-to-noise ratio (CNR) in CT images. The number of energy measurements that can be acquired simultaneously on a detector pixel is equal to the number of comparator channels. Some spectral CT designs have a limited number of comparator channels, due to the complexity of readout electronics. The spectral information could be extended by changing the comparator threshold levels over time, sub pixels, or view angle. However, acquiring more energy measurements than comparator channels increases the noise and/or dose, due to differences in noise correlations across …