Optimal rotational interval for 3-dimensional echocardiography data acquisition for rapid and accurate measurement of left ventricular function

Background: Prolonged S-dimensional echocardiography (3DE) acquisition time currently limits its routine use for calculating left ventricular volume ( LVV) and ejection fraction (EF). Our goal was to reduce the acquisition tim e by defining the largest rotational acquisition interval that still allows 3DE reconstruction for accurate and reproducible LVV and EF calculation. Methods: Twenty-one subjects underwent magnetic resonance imaging and preco rdial 3DE with 2 degrees acquisition intervals. Images were processed to re sult in data sets containing images at 2 degrees, 4 degrees, 8 degrees, 16 degrees, 32 degrees, and 64 degrees intervals by excluding images in betwee n. With use of the paraplane feature, 8 equidistant short-axis slices were generated from each data set. The suitability of these short-axis slices fo r manual endocardial tracing was scored visually by 4 independent experienc ed observers. The LVV and EF were calculated by using Simpson's rule from 3 DE data sets with 2 degrees, 8 degrees, and 16 degrees intervals, and the r esults were compared with values obtained from magnetic resonance imaging. The probability of 3DE to detect LVV and EF differences was calculated. Results: All patients were in sinus rhythm with a mean heart rate of 72 bpm (SD +/- 12). The LV short-axis images obtained with 16 degrees rotational scanning intervals allowed LV endocardial tracing in all subjects. Good cor relation, close limits of agreement, and nonsignificant differences were fo und between values of LVV and EF calculated with 3DE at 2 degrees, 8 degree s, and 16 degrees rotational intervals and those obtained with magnetic res onance Imaging. At steps of 16 degrees, 3DE had excellent correlation (r = 98, 99, and 99), close limits of agreement (+/-38, +/-28.6, and +/-4.8), an d nonsignificant differences (P = .5, .8, and .2) with values obtained from magnetic resonance imaging for calculating end-diastolic LVV, end-systolic LVV, and EF, respectively. Three-dimensional echocardiography with use of 16 degrees rotational intervals could detect 15-mL differences in end-diast olic volume with a probability of 95%, 11-mL differences in endsystolic vol ume with a probability of 92%, and 0.02 differences in. EF with a probabili ty of 95%. Conclusions: The 3DE data sets reconstructed with images selected at 16 deg rees intervals from data sets obtained at 20 precordial rotational acquisit ion intervals allowed the generation of LV short-axis images with adequate quality for endocardial border-tracing. Therefore precordial acquisition at 16 degrees intervals would be sufficient for the reconstruction of 3DE dat a sets for LV function measurement. This would reduce the acquisition time while maintaining enough accuracy for clinical decision making and would th us make 3DE more practical as a routine method.