We have investigated the multi-energy performance of our most recent prototype CT scanner with CdTe-based counting detector. With its small pixel pitch of 225 μm this device is prepared for the high X-ray fluxes occurring in clinical CT. Each of these pixels is equipped with two adjustable counters. The ASIC architecture of the detector allows configuration of the counter thresholds in chess patterns, enabling data acquisition in up to four energy bins. We have studied the material separation capability of counting CT with respect to potential clinical applications. Therefore we have analyzed contrast and noise properties in material decomposed CT images using up to four base materials. We have studied contrast agents containing iodine, gadolinium, or gold, and the body-like materials calcium, fat, and water. We describe the mathematical framework used in this work and demonstrate the general multi-energy capability of counting CT with simulations and experimental data from our prototype scanner. To prove the clinical relevance of our studies we compare the results to those obtained with well-established dual-kVp techniques recorded at same patient dose and with identical image sharpness.

Date Published: 6 March 2013
PDF: 8 pages
Proc. SPIE 8668, Medical Imaging 2013: Physics of Medical Imaging, 86680O (6 March 2013); doi: 10.1117/12.2006747

Published in SPIE Proceedings Vol. 8668:
Medical Imaging 2013: Physics of Medical Imaging
Robert M. Nishikawa; Bruce R. Whiting; Christoph Hoeschen, Editor(s)