A time-saving method was devel oped to label red blood cells in vitro with 99mTc while avoiding centrifuga tion. After tin incubation, extracellu lar tin was oxidized by sodium hypochlorite, and EDTA was added for stabilizing the complex prior to 99mTc incubation. Labeling yields were 95%, and in vivo decay showed a high stability with a mean biologic half-life of eleven hours.
The first-passage radionuclide technique for determination of car diac output using the above-men tioned tracer was evaluated by using the left ventricle as area-of-interest with individual background correc tion after complete mixing of the tracer. This technique showed a high level of agreement with invasive methods.
By combining this method for measurement of the forward stroke volume with the multigated equilib rium principle for determination of the total left ventricular stroke vol ume using similar background cor rections, an exact evaluation of re gurgitation fractions was obtained. In patients with aortic and mitral valve disease the noninvasive radio nuclide technique gave similar but probably more accurate results as compared with contrast aortography and ventriculography. The radionu clide technique may be suitable for monitoring and selecting patients for surgical treatment.
Get full access to this article
View all access options for this article.
References
1.
Nelson WS, Molnar W., Klassen KP, et al: Aortic valvulography and ascending aortography. Radiology70:697-712, 1958.
2.
Cohn LH, Mason DT, Ross J., et al: Preoperative assessment of aortic regurgitation in patients with mitral valve disease. Am J Cardiol19:177-182, 1967.
3.
Wexler L., Silverman JF, DeBush RF, et al: Angiographic features of rheumatic and nonrheumatic mitral regurgitation . Circulation44:1080-1086, 1971 .
4.
Neumann P., Schica H., Schürnbrand P., et al: Visualizing cardiac blood pool: Comparison of three labeling methods. Eur J Nucl Med8:463-466, 1983.
5.
Smith TD, Richards P.: A simple kit for the preparation of technetium-99m-labeled red blood cells . J Nucl Med17:126-132, 1976.
6.
Hegge FN, Hamilton GW, Larson SM: Cardiac chamber imaging: A comparison of in vitro and in vivo technetium-99m labeled red blood cells. J Nucl Med19:129-134, 1978.
7.
Kelbæk H., Gjørup T., Fogh J.: In vivo stability of in vitro labeled technetium-99m-red blood cells for radionuclide determination of left ventricular ejection fractions and volumes. Nucl Med Commun7:541-547, 1986.
8.
Srivastava SC , Chervu LR: Radionuclide-labeled red blood cells: Current status and future prospects. Semin Nucl Med14:68-82, 1984.
9.
Kelbæk H.: Technetium-99m labeling of red blood cells: In vitro evaluation of a new approach . J Nucl Med27:1770-1773, 1986 .
10.
Kelbæk H., Bülow K., Aldershvile J., et al: A new 99mTcred blood cell labeling procedure for cardiac blood pool imaging: Clinical results (unpublished data).
11.
Donato L.: Basic concepts of radiocardiography. Semin Nucl Med3:111-130, 1973.
12.
Lassen NA, Perl W.: Volume, flow or mass, flux ratio (mean transit time): Bolus injection. In: Tracer Kinetic Methods in Medical Physiology. New York: Raven Press, 1979, pp 76-101.
13.
Kelbæk H., Gjørup T., Hartling OJ, et al: The influence of a background correction that considers the heart volume on radionuclide left ventricular ejection fraction determination . Br J Radiol58:993-996, 1986.
14.
Kelbæk H., Gjørup T., Brynjolf I., et al: Acute effects of alcohol on left ventricular function in healthy subjects at rest and during upright exercise. Am J Cardiol55:164-167, 1985.
15.
Kelbæk H., Hartling OJ, Gjørup T., et al: Effects of autonomic blockade on cardiac function at rest and during upright exercise in humans. J Appl Physiol63:554-557, 1987.
16.
Kelbæk H., Jensen H., Madsen PV, et al: Determination of cardiac output by first passage radiocardiography: Theoretical considerations and phantom studies. Scand J Clin Lab Invest47:469-474, 1987.
17.
Kelbæk H., Hartling OJ, Skagen K., et al: First-pass radionuclide determination of cardiac output: An improved gamma camera method. J Nucl Med28:1330-1334, 1987.
18.
Kelbæk H., Heslet L., Skagen K., et al: First passage radionuclide cardiography for determination of cardiac output: Evaluation of an improved method (unpublished data).
19.
Kelbæk H., Svendsen JH, Aldershvile J., et al: Noninvasive measurement of stroke volume and left ventricular ejection fraction. Acta Radiol (in press).
20.
Rigo P., Alderson PO, Robertson RM, et al: Measurement of aortic and mitral regurgitation by gated cardiac blood pool scans. Circulation60:306-312, 1979.
21.
Marving J., Høilund-Carlsen PF, Chræmmer-Jørgensen B., et al: Are right and left ventricular ejection fractions equal?Circulation72:502-514, 1985.
22.
Kelbæk H., Aldershvile J., Svendsen JH, et al: Combined first pass and equilibrium radionuclide cardio-graphic determination of stroke volume for quantitation of valvular regurgitation . J Am Coll Cardiol (in press).
23.
Austen WG, Edwards JE, Frye RL, et al: A reporting system on patients evaluated for coronary artery disease. Circulation51:7-40, 1975.
24.
Delany DJ: Aortography. In: Cardiac Catheterization and Angiography, ed. by Grossman W.Philadelphia : Lea and Febiger, 1980, pp 197-211.
