Radionuclide detection, localization, and quantitation of intracardiac shunts and shunts between the great arteries

Abstract

T HE application of radionuclides to the study of the cardiovascular system was first investigated by Blumgart and Yens’ and Blumgart and Weiss” nearly one-half century ago, when they used radium-C and a primitive radiation detector in a series of studies on the velocity of blood flow. Over 25 yr ago, Prinzmetal described the radiocardiogram in three patients with congenital heart disease using ‘“‘I-NaI and a Geiger-Mueller counter.3.’ However, the most rapid advances in cardiovascular nuclear medicine have been made in the last decade. The advent of the scintillation camera and short-lived radionuclides have made dynamic imaging of the heart possible.” Even more recently, digital computers have made the rapid and accurate analysis of these studies a reality” by obtaining important hemodynamic parameters noninvasively, at times replacing cardiac catheterization. The radionuclide techniques to be discussed rely on the indicator dilution theory, which has been the subject of several good reviews.7-‘4 This article will concentrate on the unique capabilities offered by radionuclides for the detection, localization, and quantitation of intracardiac shunts and shunts between the great vessels (the reader is also referred to other reviews on this subject’“-“7). These radionuclide techniques are most valuable in detecting simple cardiac defects; definition of more complex malformations usually requires more invasive diagnostic methods.