Spectral response compensation for photon-counting clinical x-ray CT using sinogram restoration

Somesh Srivastava; Jochen Cammin; George S. K. Fung; Benjamin M. W. Tsui; Katsuyuki Taguchi

doi:10.1117/12.911394

2 March 2012 Spectral response compensation for photon-counting clinical x-ray CT using sinogram restoration

Somesh Srivastava, Jochen Cammin, George S. K. Fung, Benjamin M. W. Tsui, Katsuyuki Taguchi

Proceedings Volume 8313, Medical Imaging 2012: Physics of Medical Imaging; 831311 (2012) https://doi.org/10.1117/12.911394
Event: SPIE Medical Imaging, 2012, San Diego, California, United States

Abstract

The x-ray spectrum recorded by a photon-counting x-ray detector (PCXD) is distorted due to the following physical effects which are independent of the count rate: finite energy-resolution, Compton scattering, charge-sharing, and Kescape. If left uncompensated, the spectral response (SR) of a PCXD due to the above effects will result in image artifacts and inaccurate material decomposition. We propose a new SR compensation (SRC) algorithm using the sinogram restoration approach. The two main contributions of our proposed algorithm are: (1) our algorithm uses an efficient conjugate gradient method in which the first and second derivatives of the cost functions are directly calculated analytically, whereas a slower optimization method that requires numerous function evaluations was used in other work; (2) our algorithm guarantees convergence by combining the non-linear conjugate gradient method with line searches that satisfy Wolfe conditions, whereas the algorithm in other work is not backed by theorems from optimization theory to guarantee convergence. In this study, we validate the performance of the proposed algorithm using computer simulations. The bias was reduced to zero from 11%, and image artifacts were removed from the reconstructed images. Quantitative K-edge imaging in possible only when SR compensation is done.

Citation Download Citation

Somesh Srivastava, Jochen Cammin, George S. K. Fung, Benjamin M. W. Tsui, and Katsuyuki Taguchi "Spectral response compensation for photon-counting clinical x-ray CT using sinogram restoration", Proc. SPIE 8313, Medical Imaging 2012: Physics of Medical Imaging, 831311 (2 March 2012); https://doi.org/10.1117/12.911394

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