Radiology, Vol 138, 429-435, Copyright © 1981 by Radiological Society of North America
A simplified technique for measuring right ventricular ejection fraction using the equilibrium radionuclide angiocardiogram and the slant-hole collimator
BL Holman, J Wynne, JS Zielonka and JD Idoine
The authors developed and tested a simplified technique for measuring the
right ventricular ejection fraction (RVEF). Following in vivo 99mTc red
cell labeling, equilibrium (ECG-gated) radionuclide angiocardiography was
performed in the modified left-anterior-oblique projection using a 30
degree slant-hold collimator. A single region-of- interest was defined from
the ejection fraction image, and background was corrected. In 11 normal
patients, the mean RVEF was 0.59 +/- 0.08 (SD). In 20 patients with
suspected disease, who had RVEF measured by both equilibrium and first-pass
techniques, the correlation between the two methods was excellent (r =
0.95; RVEF [first-pass] = 0.74 RVEF [equilibrium] + 0.03; Sy,x = 0.05).
Interobserver correlation was also excellent (r = 0.98; Sy,x = 0.03), as
was the correlation between RVEFs measured at least 60 minutes apart (r =
0.98; Sy,x = 0.03). This method was more accurate than alternative
techniques, using either a background region-of-interest adjacent to the
right ventricle or a fixed right ventricular region-of-interest which
included the infundibulum. This simplified technique provides a
reproducible method for the sequential quantitative assessment of right
ventricular performance.
