Measurement of the ventricular stroke volume ratio by gated radionuclide angiography.

The ventricular stroke volume ratio or VSVR (left/right) was measured by gated radionuclide angiography in 33 normal subjects, using a 30 degree caudal slant-hole collimator and computer-generated functional images to aid in definition of the right ventricle. The mean ratio was found to be 1.06 +/- 0.05, compared to the normal value of 1.00. Comparative studies indicated that definition of the right ventricle based on the end-diastolic frame alone or standard collimation without caudal angulation commonly causes overestimation of the VSVR and considerably greater variance between measurements. Such errors are the result of inadequate atrioventricular separation and/or underestimation of the right-ventricular region.