Radioisotopic measurements of coronary blood flow

This review has presented a critical evaluation of current methods used in measurement of total and regional blood flow. Measurement of total coronary blood flow furnishes little evidence of pathological processes within the coronary vascular system. However, in conjunction with coronary vasodilators, measurement of total coronary blood flow may indicate the presence of coronary artery disease. Difficulties inherent in the determination of regional coronary blood flow lie primarily in defining clearance slopes and in the presence of accidental counts. More promising are methods using scintigraphs obtained with radioactive particles injected into the coronary artery. However, these procedures do not measure flow, only flow distribution. A procedure for measuring regional uptake of positron emitters by coincidence counting has been described; the method posesses definite advantages over other procedures, since it is noninvasive and appears to have good resolution. However, the method is dependent on higher decay density which necessitates the use of nuclides with a short half-life