BIFOCAL DIVERGING COLLIMATOR - MEANS OF SIMULTANEOUS BIPLANE IMAGING OF THE HEART DURING EQUILIBRIUM RADIONUCLIDE VENTRICULOGRAPHY

Abstract

A bifocal diverging collimator (BDC) was constructed capable of stimultaneously recording 2 views of the heart 50.degree. apart on each half of a standard imaging field. Simultaneous 2-view blood-pool scans using the BDC were compared to the same 2 separate views obtained using an all-purpose parallel-hole collimator (PHC) assessing left-ventricular ejection fraction and regional wall motion in 20 patients undergoing contrast left ventriculography (CV). Ejection fraction by BDC correlated closely with PHC (r [correlation coefficient] = 0.94) and with CV (r = 0.88). Regional wall motion was scored qualitatively on a 5-point scale from 3 (normal) to -1 (dyskinesis) with an 88% agreement between BDC and PHC for segment scores. The percentages for agreement between BDC and CV and between PHC and CV were identical, 79%. A single blood-pool scan acquisition using a new BDC provides information about global and regional left-ventricular function in 2 planes comparable with that of a PHC. [Cardiac blood-pool scanning at rest has been used to assess global and regional left-ventricular function in coronary artery disease.].