Abstract
Background
The purpose of this study was to determine the relative image quality and interobserver variability among four readers for201Tl and99mTc-labeled tetrofosmin myocardial perfusion images.99mTc-labeled perfusion agents, with near-optimal physical characteristics for gamma camera imaging, may allow for superior image quality and improved consistency of interpretation. However, most studies to date have demonstrated only similarity in the diagnostic accuracy between technetium agents and thallium. Tetrofosmin is a recently developed99mTc-labeled agent that has shown promising results in early clinical trials.
Methods and Results
A multicenter, open-label trial was performed during which treadmill exercise thallium and tetrofosmin scintigraphy was performed within a 2-week period of each other in 216 subjects. Image quality was evaluated subjectively and scans were interpreted in a blinded, independent fashion by four readers. Perfusion abnormalities were graded as consistent with ischemia, infarction, or mixed and were described both globally and regionally. Interobserver variability was assessed by use of the κ statistic, and receiver-operator curves were compared for each observer for the diagnostic accuracy of each agent. More tetrofosmin images were of excellent quality than with thallium (52% vs 28%;p<0.05), and when differences in quality were noted between the agents, tetrofosmin was more often superior (p<0.0001). The interobserver variability was lower with tetrofosmin scintigraphy because generally higher κ values were noted, especially in the lateral wall. Higher receiver-operator curve areas indicative of improved diagnostic accuracy were noted among the four readers for tetrofosmin in 80% of vascular territories.
Conclusions
99mTc-labeled tetrofosmin scintigraphy yields images of improved quality compared with thallium, and there is an overall improvement in the consistency of image analysis associated with the use of tetrofosmin.
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References
Wackers FJT, Berman DS, Maddahi J, et al. Animal and human studies of a new methoxyisobutyl isonitrile: human biodistribution, dosimetry, safety, and preliminary comparison to thallium-201 for myocardial perfusion imaging. J Nucl Med 1989;30:301–11.
Kiat H, Maddahi J, Roy LT, et al. Comparison of technetium-99m-methoxy isobutyl isonitrile and thallium-201 for evaluation of coronary heart disease by planar and tomographic methods. Am Heart J 1989;117:1–11.
Hendel RC, McSherry B, Karimeddini M, Leppo JA. Diagnostic value of a new myocardial perfusion agent, teboroxime (SQ30,217), utilizing a rapid planar imaging protocol: preliminary results. J Am Coll Cardiol 1990;16:855–61.
Kelly JD, Forster AM, Higley B, et al. Technetium-99m-tetrofosmin as a new radiopharmaceutical for myocardial perfusion imaging. J Nucl Med 1993;34:222–7.
Highley B, Smith FW, Smith T, et al. Technetium-99m-1,2-bis[bis(2-ethoxyethy)phosphino]ethane: human biodistribution, dosimetry and safety of a new myocardial perfusion imaging agent. J Nucl Med 1993;34:30–8.
The Tetrofosmin Study Group. Comparative myocardial perfusion imaging with Tc-99m tetrofosmin and thallium-201: results of phase-III international trial. Circulation 1992;86(suppl):I-506.
Wackers FJT, Fetterman RC, Mattera JA, Clements JP. Quantitative planar thallium-201 stress scintigraphy: a critical appraisal of the method. Semin Nucl Med 1985;15:46–66.
Cohen J. A coefficient of agreement for nominal scales. Educ Psychol Measmt 1960;20:37–46.
Landis JR, Koch GG. The measure of observer agreement for categorical data. Biometrics 1977;33:159–74.
Fleiss JL. Statistical methods for rates and proportions. 2nd ed. New York: John Wiley & Sons, 1981:212–36.
Metz CE. Basic principles of ROC analysis. Semin Nucl Med 1978;8:283–98.
Trobaugh GB, Wackers FJT, Busemann E, DeRouen, Richie JL, Hamilton GW. Thallium-201 myocardial imaging: an interinstitutional study of observer variability. J Nucl Med 1978;19:359–63.
Wackers FJT, Bodenheimer M, Fleiss JL, et al. Factors affecting uniformity in interpretation of planar thallium-201 imaging in a multicenter trial. J Am Coll Cardiol 1993;21:1064–74.
Atwood JE, Jensen D, Froelicher V, et al. Agreement in human interpretation of analog thallium myocardial perfusion images. Circulation 1981;64:601–9.
Okada RD, Boucher CA, Kirshenbaum HK, et al. Improved diagnostic accuracy of thallium-201 stress test using multiple observers and criteria derived from interobserver analysis of variance. Am J Cardiol 1980;46:619–24.
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Supported by Amersham Healthcare, Medi-Physics, Inc., Arlington Heights, Ill.
All editorial decisions for this article, including selection of reviewers and the final decision, were made by a guest editor. This procedure applies to all manuscripts with authors from Yale University, School of Medicine.
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Hendel, R.C., Parker, M.A., Wackers, F.J.T. et al. Reduced variability of interpretation and improved image quality with a technetium 99m myocardial perfusion agent: Comparison of thallium 201 and technetium 99m-labeled tetrofosmin. J Nucl Cardiol 1, 509–514 (1994). https://doi.org/10.1007/BF02939973
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DOI: https://doi.org/10.1007/BF02939973