Modeling photon-counting detectors for x-ray CT: spectral response
and pulse-pileup effects and evaluation using real data

J. Cammin; J. Xu; William C. Barber; J. S. Iwanczyk; N. E. Hartsough; K. Taguchi

doi:10.1117/12.2008077

19 March 2013 Modeling photon-counting detectors for x-ray CT: spectral response and pulse-pileup effects and evaluation using real data

J. Cammin, J. Xu, William C. Barber, J. S. Iwanczyk, N. E. Hartsough, K. Taguchi

Author Affiliations +

Proceedings Volume 8668, Medical Imaging 2013: Physics of Medical Imaging; 86680R (2013) https://doi.org/10.1117/12.2008077
Event: SPIE Medical Imaging, 2013, Lake Buena Vista (Orlando Area), Florida, United States

Abstract

Spectral computed tomography (CT) with photon-counting detectors (PCDs) has the potential to substantially advance diagnostic CT imaging by reducing image noise and dose to the patient, by improving contrast and tissue specificity, and by enabling molecular and functional imaging. The current PCD technology, however, is limited by two main factors: imperfect energy measurement (spectral response effects, SRE) and limited count rate (pulse-pileup effects, PPE, due to detector dead-times). The overall goal of our research is to develop compensation algorithms for these sources of data distortions, to demonstrate that PCDs are suitable for clinical CT, and to identify key clinical applications for spectral CT with PCDs. We have already developed an iterative compensation scheme that includes a forward projection model of the imaging chain and that can compensate for either SRE or PPE distortions separately by maximizing a penalized log-likelihood function. In this paper we describe the evaluation of a combined, cascaded SRE and PPE model for PCDs and compare the models to data acquired with an experimental table-top PCD-CT system. The separation into count-rate independent effects (SRE) and count-rate dependent effects (PPE) allows cascading the forward model. First, the SRE model is evaluated using low count rates. Then the PPE model is cascaded and the combined SRE+PPE model is evaluated. Several different attenuators were used, including K-edge materials and the models and data were compared for various count-rate conditions.

Citation Download Citation

J. Cammin, J. Xu, William C. Barber, J. S. Iwanczyk, N. E. Hartsough, and K. Taguchi "Modeling photon-counting detectors for x-ray CT: spectral response and pulse-pileup effects and evaluation using real data", Proc. SPIE 8668, Medical Imaging 2013: Physics of Medical Imaging, 86680R (19 March 2013); https://doi.org/10.1117/12.2008077

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available