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

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: jnumed.107.040535v1 48/7/1090    most recent 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 Similar articles in PubMed 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 Goetze, S. Articles by Bengel, F. M. Search for Related Content PubMed PubMed Citation Articles by Goetze, S. Articles by Bengel, F. M.

Attenuation Correction in Myocardial Perfusion SPECT/CT: Effects of Misregistration and Value of Reregistration

¹ Division of Nuclear Medicine, Johns Hopkins University, Baltimore, Maryland; ² Division of Nuclear Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and ³ Division of Biostatistics, Johns Hopkins University, Baltimore, Maryland

Correspondence: For correspondence contact: Frank M. Bengel, MD, Division of Nuclear Medicine/PET, 601 N. Caroline St., JHOC 3225, Baltimore, MD 21287-0817. E-mail: fbengel1{at}jhmi.edu

The accuracy of myocardial perfusion SPECT improves with attenuation correction. Algorithms for attenuation correction in hybrid SPECT/CT systems have the potential for misregistration of emission and transmission scans because CT and SPECT are obtained sequentially. Misregistration will influence regional tracer distribution and may reduce diagnostic accuracy. This study focused on the role of misregistration in cardiac SPECT/CT and the performance of a software-based approach for reregistration. Methods: We included 105 consecutive patients who underwent clinical myocardial perfusion imaging on a SPECT/CT system. Images were quantitatively assessed for misregistration using fusion software. Results were recorded in millimeters in the x-, y-, and z-axes. Regional tracer uptake in 6 segments (anterior, septal, inferior, lateral, anteroapical, and inferoapical) for noncorrected and attenuation-corrected images before and after reregistration was obtained from polar maps. To determine the relative influence of misregistration, we correlated individual differences between noncorrected and attenuation-corrected images, as well as between attenuation-corrected images before and after reregistration, with the degree of misregistration in a multivariate analysis including additional clinical variables such as sex and body weight. Results: The difference in regional radiotracer uptake was significant between noncorrected and attenuation-corrected images in all 6 segments and was most pronounced in the inferior wall. On multivariate analysis, misregistration contributed significantly to changes in radiotracer distribution in the anterior (P = 0.038), septal (P = 0.011), and inferior (P = 0.006) segments. The mean misregistration was 8.6 ± 3.8 mm (1.25 ± 0.55 pixel). Misregistration of one or more pixels was observed in 64% of studies. Reregistration of misalignment significantly affected regional radiotracer distribution in the segments shown to be influenced by misregistration. Conclusion: Misregistration occurs with SPECT/CT systems and influences regional tracer distribution on attenuation-corrected myocardial images. Reregistration of misaligned studies may be a useful tool for correction. The impact of this strategy on the diagnostic and prognostic accuracy of cardiac hybrid imaging needs to be determined.

Key Words: SPECT/CT • hybrid imaging • attenuation correction • myocardial perfusion imaging

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:

				M. S. Javadi, R. Lautamaki, J. Merrill, C. Voicu, W. Epley, G. McBride, and F. M. Bengel Definition of Vascular Territories on Myocardial Perfusion Images by Integration with True Coronary Anatomy: A Hybrid PET/CT Analysis J. Nucl. Med., February 1, 2010; 51(2): 198 - 203. [Abstract] [Full Text] [PDF]

				J. A. Kennedy, O. Israel, and A. Frenkel Directions and Magnitudes of Misregistration of CT Attenuation-Corrected Myocardial Perfusion Studies: Incidence, Impact on Image Quality, and Guidance for Reregistration J. Nucl. Med., September 1, 2009; 50(9): 1471 - 1478. [Abstract] [Full Text] [PDF]

				A. K. Buck, S. Nekolla, S. Ziegler, A. Beer, B. J. Krause, K. Herrmann, K. Scheidhauer, H.-J. Wester, E. J. Rummeny, M. Schwaiger, et al. SPECT/CT J. Nucl. Med., August 1, 2008; 49(8): 1305 - 1319. [Abstract] [Full Text] [PDF]

				T. Higuchi and F. M Bengel Cardiovascular nuclear imaging: from perfusion to molecular function Heart, June 1, 2008; 94(6): 809 - 816. [Full Text] [PDF]