HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JNM Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Teo, B.-K. Articles by Franc, B. L. Search for Related Content PubMed Articles by Teo, B.-K. Articles by Franc, B. L.

Partial-Volume Correction in PET: Validation of an Iterative Postreconstruction Method with Phantom and Patient Data

¹ Department of Radiology, University of California, San Francisco, San Francisco, California; ² National Institutes of Health, Bethesda, Maryland; and ³ Siemens Oncology Care Systems, Concord, California

Correspondence: For correspondence or reprints contact: Boon-Keng Teo, PhD, Department of Radiology, University of California, San Francisco, 185 Berry St., Suite 350, San Francisco, CA 94107. E-mail: kteo{at}radiology.ucsf.edu

Partial-volume errors (PVEs) in PET can cause incorrect estimation of radiopharmaceutical uptake in small tumors. An iterative postreconstruction method was evaluated that corrects for PVEs without a priori knowledge of tumor size or background. Methods: Volumes of interest (VOIs) were drawn on uncorrected PET images. PVE-corrected images were produced using an iterative 3-dimensional deconvolution algorithm and a local point spread function. The VOIs were projected on the corrected image to estimate the PVE-corrected mean activity concentration. These corrected mean values were compared with uncorrected maximum and mean values. Simulated data were generated as a first test of the correction algorithm. Phantom measurements were made using ¹⁸F-FDG–filled spheres in a scattering medium. Clinical validation used 154 surrogate tumors from 9 patients. The surrogate tumors were blood-pool images of the descending aorta as well as mesenteric and iliac arteries and veins. Surrogate tumors ranged in diameter from 5 to 25 mm. Analysis used ¹⁸F-FDG and ¹¹C-CO datasets (both dynamic and static). Values representing "truth" were derived from imaging the blood pool in large structures (e.g., the left ventricle, left atrium, or sections of the aorta) where PVEs were negligible. Surrogate tumor sizes were measured from contrast CT. Results: The PVE-correction technique, when applied to the mean value in spheric phantoms, yielded recovery coefficients of 87% for an 8-mm-diameter sphere and between 100% and 103% for spheres between 13 and 29 mm. For the human studies, PVE-corrected data recovered a large fraction of the true activity concentration (86% ± 7% for an 8-mm-diameter tumor and 98% ± 8% for tumors between 10 and 24 mm). For tumors smaller than 18 mm, the PVE-corrected mean values were less biased (P < 0.05) than the uncorrected maximum or mean values. Conclusion: Iterative postreconstruction PVE correction generated more accurate uptake measurements in subcentimeter tumors for both phantoms and patients than the uncorrected values. The method eliminates the requirement for segmenting anatomic data and estimating tumor metabolic size or tumor background level. This technique applies a PVE correction to the mean voxel value within a VOI, yielding a more accurate estimate of uptake than the maximum voxel value.

Key Words: PET/CT imaging • partial-volume errors • quantification • iterative reconstruction

COPYRIGHT © 2007 by the Society of Nuclear Medicine, Inc.

Related articles in JNM:

This Month in JNM

JNM 2007 48: 11a-12a. [Full Text]  

This article has been cited by other articles:

				J. H.F. Rudd, K. S. Myers, S. Bansilal, J. Machac, C. A. Pinto, C. Tong, A. Rafique, R. Hargeaves, M. Farkouh, V. Fuster, et al. Atherosclerosis Inflammation Imaging with 18F-FDG PET: Carotid, Iliac, and Femoral Uptake Reproducibility, Quantification Methods, and Recommendations J. Nucl. Med., June 1, 2008; 49(6): 871 - 878. [Abstract] [Full Text] [PDF]

				I. Buvat, S. L. Bacharach, and M. Soret Reply: Feasibility of Automated Partial-Volume Correction of SUVs in Current PET/CT Scanners: Can Manufacturers Provide Integrated, Ready-to-Use Software? J. Nucl. Med., June 1, 2008; 49(6): 1032 - 1033. [Full Text] [PDF]

				M. Soret, S. L. Bacharach, and I. Buvat Partial-Volume Effect in PET Tumor Imaging J. Nucl. Med., June 1, 2007; 48(6): 932 - 945. [Abstract] [Full Text] [PDF]