Validation of left ventricular volume measurements by gated SPECT Tc-99m-labeled sestamibi imaging

Background. Previous studies have shown that gated single photon emission c omputed tomography (SPECT) technetium 99-labeled sestamibi imaging provides accurate and reproducible measurement of left ventricular (LV) ejection fr action (EF), wall motion, and thickening. This study examined the reliabili ty of gated SPECT sestamibi imaging in measuring LV end-diastolic volume (E DV), end-systolic volume (ESV), and stroke volume (SV), Methods and Results, Gated SPECT measurements were compared with an indepen dent nongeometric method based on thermodilution SV and first-pass radionuc lide angiographic EF (using a multicrystal gamma camera), Twenty-four patie nts aged 58 +/- 11 years underwent cardiac catheterization and coronary ang iography for evaluation of chest pain syndromes. None had primary valvular disease, intracardiac shunts, or atrial fibrillation, Results. The correlat ion between the two methods mere as follows: EDV: r = 0.89, P < .001; ESV: r = .938, P < .001; SV: r = 0.577, P < .001. Bland-Altman plots showed mean differences (+/- standard deviation [SD]) for EDV of -14.3 +/- 33.3 mt, fo r ESV of -0.4 +/- 23.7 mt, and for SV of -13.9 +/- 15.2 mt. The reproducibi lity of measuring EDV and ESV by gated SPECT was very high (r = 0.99 each). Conclusion, Gated Tc-99m-labeled sestamibi SPECT provides reproducible LV v olume measurements. With validation of volume measurement, gated SPECT prov ides comprehensive assessment of regional and global LV function. This info rmation is important in many patient groups such as those with ischemic car diomyopathy, concomitant coronary and valve disease, and those who have had myocardial infarction, It will also be useful to assess the incremental va lue of LV volumes in risk assessment.