Cart (Loading....) | Create Account
Close category search window
 

Using linear time-invariant system theory to estimate kinetic parameters directly from projection measurements

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Zeng, G.L. ; Dept. of Radiol., Utah Univ., Salt Lake City, UT, USA ; Gullberg, G.T. ; Huesman, R.H.

In a dynamic SPECT (single photon emission computed tomography) study, if an image is reconstructed for each detector rotation, the image will contain errors as the data for each projection angle are acquired at different times in the dynamic study. These errors will affect the kinetic parameter estimation. We hypothesize that more accurate estimates can be obtained if the parameters are estimated directly from the projections than from the reconstructions. It is more difficult to estimate the parameters from the projections than from the reconstructions. In the reconstructed images, all the regions are well separated, while in projections the regions are mixed. Estimation from the projections requires all projections of the kinetic models for each region. This results in a relatively complicated objective function, which is usually not well behaved and has many local minima due to the non-linear exponential terms. We propose a technique to estimate the exponential parameters separately using a linear model, which has a closed-form solution for the one parameter case and has a unique solution via the singular value decomposition (SVD) for the multiple parameter case. The other multiplicative parameters also have a linear model and are estimated once the exponential parameters have been fixed. The objective function with fixed exponential parameters is quadratic and well-behaved. No local minima are observed in computer simulations, which enabled us to obtain accurate estimation. Our computer simulations demonstrate that estimation directly from the projections are more accurate than the estimation from the reconstructed images

Published in:

Nuclear Science Symposium and Medical Imaging Conference, 1994., 1994 IEEE Conference Record  (Volume:4 )

Date of Conference:

30 Oct-5 Nov 1994

Need Help?


IEEE Advancing Technology for Humanity About IEEE Xplore | Contact | Help | Terms of Use | Nondiscrimination Policy | Site Map | Privacy & Opting Out of Cookies

A not-for-profit organization, IEEE is the world's largest professional association for the advancement of technology.
© Copyright 2014 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.