Right ventricular ejection fraction measured by first-pass intravenous krypton-81m: reproducibility and comparison...

Study of the effects of various diseases and therapeutic manipulation of pulmonary vascular resistance on the right ventricle has been restricted by methodologic limitations. The radioactive gas in solution, krypton-81m was used to study the right ventricle and the technique was compared with a technetium-99m method. In 22 subjects, first-pass krypton-81m right ventricular ejection fraction, acquired both in list mode and electrocardiogram-gated frame mode, correlated well (r = 0.81 and 0.86, respectively, p less than 0.01) with that determined by technetium-99m first-pass studies over a broad range of ventricular function. The reproducibility of the technique was excellent (r = 0.84 and 0.95 for each acquisition mode, respectively). Krypton-81m first-pass studies provide accurate and reproducible estimates of right ventricular function. Use of krypton allows multiple measurements, with or without perturbations, over a short period of time.