Basic evaluation of an ambulatory ventricular function monitor with cadmium telluride detector

The reliability of a new ambulatory ventricular function monitor (VEST) with cadmium telluride (Cd-Te) detector was validated. No counting loss was observed under 20 kcps. In phantom study, more than 200 ml with 6 cm distance from the detector and more than 300 ml with 6-12 cm distance, underestimation of volume was observed. Ejection fraction (EF) calculated in phantom study showed close value to the true EF in 50-400 ml of end-diastolic volume. In 10 patients, 1-2 cm detector shift toward right upper, upper and left showed underestimation of EF. Good correlation of gamma camera EF (X) and VEST EF (Y) was obtained (Y=0.96X + 3.6(%), n=37, r=0.93, p<0.001). EF change from rest values, obtained from each comparable exercise and post exercise stage by gamma camera (X) and VEST (Y), showed good correlation (Y=0.95X + 0.8, n=20, r=0.85, p<0.001). In conclusion, Cd-Te VEST was considered as a reliable EF measurement technique similar to gamma camera. (author)