Abstract
The authors carried out experimental and clinical studies of left ventricular volume measurement using equilibrium-gated blood pool scan. Using phantoms, we experimentally obtained a regression equation between radioisotope levels and camera counts. From this equation, we deduced a regression equation between camera counts and volumes, which was then used for calculation of left ventricular volumes using count technique. In an experiment using phantom with various volumes, we obtained a favorable result that the average absolute error between the true and measured volumes was as small as 6.8 %. In 11 patients, we calculated the left ventricular volume and ejection fraction employing the regression equation and compared the calculated values with the values obtained by cinemascopy. This comparison disclosed an excellent correlation (r=0.955 for end-diastolic volume, 0.997 for end-systolic' volume and 0.853 for ejection fraction) . Mean absolute error was 16.2% for end-diastolic volume and 16.0% for end-systolic volume. These results indicate that this technique is clinically applicable.
