By Topic

Validation of CT-based attenuation correction for multi-pinhole PSF reconstruction for small-animal SPECT

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
$33 $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

7 Author(s)
Derek W. Austin ; Siemens Medical Solutions, USA, Inc., Molecular Imaging, Preclinical Solutions, Knoxville, TN 37932 USA ; Bing Feng ; Robert A. Mintzer ; Mu Chen
more authors

We recently reported a numerical ray-tracing algorithm for calculating the point-spread function (PSF) used in 3-D ordered subsets expectation maximization (OSEM) reconstruction of single and multi-pinhole collimated single photon emission computed tomography (SPECT) images. In this work, we evaluated the performance of our PSF reconstruction method with and without X-ray CT-based attenuation correction (AC) and dual energy window scatter correction (SC). X-ray CT data was acquired to create the attenuation maps. SPECT data was acquired using 99mTc phantoms and 5-pinhole tungsten collimators with 1.0 mm diameter pinholes. With no corrections applied, an axial image slice of a 3 cm diameter cylinder uniformly filled with mTc showed a 13% dip near the center of the phantom. When AC and SC were applied, the cross-section through an axial slice showed a desirable flattened profile that dipped only 3%. We also scanned a mouse with 99mTc implantable sources that had negligible self-attenuation. The sources were first scanned in air for calibration. Our results show that the reconstructed SPECT images with no corrections underestimated the activity for each mTc implanted source by 12% on average, while the image with AC and SC underestimated the activity by only 3.3% on average. We repeated all of the experiments with 125I phantoms but did not apply SC to the 125I data. With no correction applied, an axial slice of a 3 cm diameter cylinder uniformly filled with 125I dipped 25 % near the center of the phantom. After applying AC, the 125I image profile no longer dipped but rather was overcorrected by 4.5%. Similarly, the reconstructed image of the 125I implants with no correction underestimated the activity of each source by 23% on average, while the 125I image with AC overestimated the activity in the sources by 4.6% on average. These results have shown that our PSF- - reconstruction method with CT-based attenuation correction improved the quantitative accuracy of SPECT images for representative 99mTc and 125I studies.

Published in:

IEEE Nuclear Science Symposuim & Medical Imaging Conference

Date of Conference:

Oct. 30 2010-Nov. 6 2010