Abstract 9040: Three-Dimensional Speckle Feature Tracking Evaluation of Regional Left Ventricular Strain and Detection of Simulated Infarct on 4D Echocardiographic Images: An Experimental Study

Abstract

Background: Cardiac strain generated from 2D speckle-tracking is a clinical standard despite the complex 3D architecture of the left ventricle (LV). Artida 3D Wall Motion Tracking (3D-WMT) permits LV strain quantification in true 3D. We aimed to validate the circumferential and longitudinal strain (CS, LS) calculated by this 3D feature-tracking program against sonomicrometry (sono) at different stroke rates (SRs).

Methods: Five freshly harvested pig hearts were pumped at 30-70 ml stroke volumes (SVs). Full-volume data was acquired via 4D echo at SRs of 45 beats per second (bps) and 90 bps for SVs 30 and 40 ml. Additional data was recorded before and after simulated myocardial infarction (MI) at all SVs. CS and LS were calculated for each SV and SR and graphed against sono data.

Results: Both CS (R² = 0.798) and LS (R² = 0.828) have excellent linear agreement with sono data (All p<0.001). Bland-Altman analyses demonstrate overestimation at both CS (7.809) and LS (5.451), with 96% of points within a 95% CI. After MI induction, CS and LS were significantly decreased, still with a good linear relationship with sono data (CS: R² = 0.7652, LS: R² = 0.8838) (p<0.001); the overestimation was 6.098 (CS) and 7.384 (LS), 96% and 98% of points within 95% CI respectively. Low and high SRs were found to have no significant difference in terms of strain (p=0.142).

Conclusion: Toshiba’s 3D-WMT program works to determine CS and LS from 4D volumes with values comparable to sonomicrometry. Different SRs have no significant impact on analysis.