Automatic quantification of ejection fraction from gated myocardial perfusion SPECT.

TLDR

The study develops a fully automatic algorithm to quantify left ventricular ejection fraction from gated 99mTc‑sestamibi myocardial perfusion SPECT images. The algorithm automatically segments the left ventricle in 3‑D gated SPECT, estimates endocardial and epicardial surfaces across all cardiac phases, computes end‑diastolic and end‑systolic volumes, derives global ejection fraction without operator input, and was validated in 65 patients against first‑pass radionuclide ventriculography. The method achieved 100 % successful LV segmentation, showed strong agreement with first‑pass radionuclide ventriculography (r = 0.909) and excellent concordance between 16‑ and 8‑interval gated SPECT (r = 0.988), with 8‑interval values on average 3.7 % lower, confirming its rapid, accurate performance comparable to conventional EF measurements.

Abstract

We have developed a completely automatic algorithm to quantitatively measure left ventricular ejection fraction (LVEF) from gated 99mTc-sestamibi myocardial perfusion SPECT images.The algorithm operates in the three-dimensional space and uses gated short-axis image volumes. It segments the left ventricle (LV), estimates and displays endocardial and epicardial surfaces for all gating intervals in the cardiac cycle, calculates the relative left ventricular cavity volumes and derives the global EF from the end-diastolic and end-systolic volume, all without operator interaction. The algorithm for measuring LVEF was tested in 65 clinical patients undergoing 16-interval and 8-interval rest-gated SPECT and validated against first-pass radionuclide ventriculography.Automatic segmentation and contouring of the LV was successful in 65/65 (100%) of the studies. Agreement between EFs measured from 8-interval gated SPECT and EFs calculated from first-pass data was high (y = 2.44 + 1.03x, r = 0.909, p < 0.001, s.e.e. = 6.87). Agreement between EF values measured from 16-interval and 8-interval gated SPECT was excellent (y = -2.7 + 0.97x, r = 0.988, p < 0.001, s.e.e. = 2.65), the latter being on average lower by 3.71 percentage points.Our automatic method is rapid and highly agrees with conventional radionuclide measurements of EF, thus providing clinically useful additional information to complement myocardial perfusion studies.