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 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 Ford, P. V. Articles by Dhekne, R. D. Search for Related Content PubMed PubMed Citation Articles by Ford, P. V. Articles by Dhekne, R. D.

Overestimation of the LVEF by Quantitative Gated SPECT in Simulated Left Ventricles

Nuclear Medicine Section, Department of Radiology, Baylor College of Medicine, Houston; Department of Nuclear Medicine, St. Luke’s Episcopal Hospital, Houston; and Texas Heart Institute, Houston, Texas

During routine myocardial perfusion imaging, a common observation is that patients with normal cardiac function and small hearts, in particular small women, have higher left ventricular ejection fractions (LVEFs), as measured by quantitative gated SPECT (QGS) software, than anticipated, often markedly so. The goal of this project was to determine if the QGS LVEF varies with the change in end-diastolic left ventricular volume (EDV) and in particular to verify that the clinically observed phenomenon of falsely elevated QGS LVEF in patients with small hearts is actually occurring. Methods: A series of mathematically defined left ventricles (LVs) was produced by varying the EDV and targeted LVEF (tLVEF). These were created using concentric hemiellipsoids with nine different EDVs. The tLVEF was varied from 15% to 75% by 5% increments for a total of 13 different ejection fractions. These datasets were then smoothed, creating a total of 234 sets. The smoothed and unsmoothed images were then processed using QGS software. The LVEFs and EDVs were recorded. Results: For lower LVEFs the agreement between the QGS LVEF and the tLVEF is good. A marked overestimation occurs when the EDVs are low and the ejection fractions are in the higher range. This effect is greater in the smoothed images. Conclusion: An artifactual increase in the LVEF can occur when measurements are made with the QGS software. These data argue against using QGS LVEF for monitoring the LVEF in patients with small hearts. Our data imply that a mildly decreased LVEF may still appear to be in the normal range when measured by QGS software.

Key Words: ejection fraction • gating • myocardial perfusion imaging • quantitative gated SPECT software

This article has been cited by other articles:

				B. Feng, A. Sitek, and G. T. Gullberg Calculation of the Left Ventricular Ejection Fraction Without Edge Detection: Application to Small Hearts J. Nucl. Med., June 1, 2002; 43(6): 786 - 794. [Abstract] [Full Text] [PDF]