Comparison of high-resolution with high-sensitivity collimators in low-count cardiac gated blood pool studies

In exercise cardiac-gated blood pool studies, limited time is available for data acquisition at each level of exercise. The authors compared high-sensitivity and high-resolution collimators in 13 resting patients, using 2.5-minute acquisition times; high-count, high-resolution acquisitions served as standards. Ejection fractions (EFs) calculated from low-count acquisitions with each collimator were plotted against high-count calculations done with the high-resolution collimator. The difference in the variance of these plots were significant at the .1 level (.05 < P <.1). Spatial resolution was comparable. Statistical noise was greater in the high-resolution images. The high-sensitivity collimator is superior in low-count EF measurements