Both multicrystal and single-crystal detectors have been in use for mo
re than 25 years for measurement of ejection fraction by analysis of i
mages collected during the first-pass transit of radionuclides through
the heart, Originally, multicrystal cameras were preferred, because t
hey provided higher count rates than Anger cameras; however, over the
years improvements in count rate capability and collimator design have
enabled Anger cameras to perform equally well, This has become an imp
ortant issue now that readily available Tc-99m agents, such as sestami
bi, enable evaluation of both myocardial function and perfusion from a
single injection, The technical abilities of a particular camera dete
rmine which acquisition protocols are most likely to provide clinicall
y useable images for the widest spectrum of patients, Electrocardiogra
phic-gated list mode collection is highly desirable for first-pass ima
ging, providing the greatest flexibility of data review, rebinning, an
d analysis, Attention to quality control issues of data characterizati
on and processing is important to ensure accuracy and precision of all
measurements, Accurate determinations of ejection fraction of the lef
t ventricle are possible routinely and, under favorable circumstances,
of the right ventricle as well.