Radiology, Vol 135, 725-730, Copyright © 1980 by Radiological Society of North America
Influence of different background and left-ventricular assignments on the ejection fraction in equilibrium radionuclide angiography
R Slutsky, M Pfisterer, J Verba, A Battler and W Ashburn
Seventy-six patients were studied within one week of contrast
ventriculography to assess the influence of differing background
assignments on ejection fractions derived from gated equilibrium
radionuclide anigograms. "Fixed" and "variable" left-ventricular regions on
interest and five different backgrounds were used. Inter- and
intra-observer variability were determined, and 15 patients underwent a
second study 2 weeks later. Variable left-ventricular regions of interest
produced higher ejection fractions than fixed ones. A computer-assigned
background or a ring drawn manually around the left ventricle correlated
best with contrast ventriculography, giving greater serial and inter- and
intra-observer variability. Automated background assignments reduced
variability and increased reproducibility, though not always associated
with the best correlation with contrast ventriculography. Thus a variety of
left-ventricular and background regions of interest gives excellent
reproducibility and accuracy.
