title: Accuracy of left ventricular end-diastolic dimension determinations obtained by radionuclide angiocardiography.
abstract: This study tested the ability of first-pass radionuclide angiocardiography to detect accurately the left ventricular endocardial surface of the intact, conscious, chronically instrumented dog. A spherical phantom was used to define the influence of collimation: with a 1.0-in. collimator, the optimal count threshold was a border at 31% of the image's maximum counts; and with a 1.5-in. collimator, the optimal count threshold was at 21%. These were used to analyze cardioscintigrams obtained in 19 studies of six dogs. The dogs were provided with pulse transit sonomicrometer dimension transducers on the endocardium, right-atrial pacing electrodes, electrocardiographic leads, and catheters in the superior vena cava and right or left atria. The minor-axis dimension of the left ventricle was measured ultrasonically while the cardioscintigram was being stored. The minor-axis dimension and end-diastolic volume obtained by the two techniques had linear correlation coefficients of 0.95 and 0.98. This correlation indicates the inherent accuracy of radionuclide techniques by defining left-ventricular endocardial edges for a large range of volumes in the dog.
mesh_terms: D000790:Angiocardiography / Q000379:methods*; D000818:Animals; D003971:Diastole; D004285:Dogs; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D008954:Models, Biological; D011877:Radionuclide Imaging; D012044:Regression Analysis; D014465:Ultrasonics / Q000295:instrumentation