Evaluation of nonradioactive, colored microspheres for measurement of regional myocardial blood flow in dogs

• Published in: Circulation (New York, N.Y.) N.Y.), 1988-08, Vol.78 (2), p.428-434
• Main Authors: HALE, S. L, ALKER, K. J, KLONER, R. A
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cardiovascular system; Cerium Radioisotopes; Color; Coronary Circulation; Coronary Disease - physiopathology; Dogs; Female; Heart Rate; Investigative techniques of hemodynamics; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Microspheres; Niobium; Radioisotopes; Ruthenium Radioisotopes
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/01.cir.78.2.428

Measurement of regional myocardial blood flow (RMBF) is crucial in experimental studies of myocardial ischemia and reperfusion in dogs. The standard measurement technique uses radioactive microspheres; however, not all institutions are able to dispose of radioactive waste and therefore cannot make use of this method. We tested a new, nonradioactive microsphere, labeled with colors instead of nuclides. Simultaneous blood flow measurements with two nuclide-labeled and two colored microspheres were performed after coronary occlusion in dogs. Both techniques show a within-method correlation of r greater than 0.98. Duplicate variability for paired RMBF values in 80 samples was 8.7 +/- 0.1% when computed with radioactive microspheres and 13.2 +/- 1.8% when computed with colored microspheres. There was a good correlation in the measurement of RMBF between the radioactive- and colored-microsphere methods (r = 0.98). The best-fitting linear regression line was expressed by the formula: Colored-microsphere RMBF = 1.11 (radioactive-microsphere RMBF)-0.02. When measured by colored microspheres, RMBF was approximately 8% higher than when computed with radioactive microspheres for blood flow values of 0-2 ml/min/g. When blood flow was increased pharmacologically to levels of 2-7.5 ml/min/g, colored microspheres yielded blood flow values 39% higher than the values computed by radioactive microspheres. We conclude that the nonradioactive, colored-microsphere method correlates with the radioactive technique, but at high flows, it yields values greater than those obtained with radioactive microspheres.