Abstract 9441: Three-Dimensional Speckle Tracking Echocardiography for Evaluating Left Ventricular Rotation: An in vitro Validation Study using a Rotational Phantom Model
Background: Left ventricular (LV) rotation provides an index of regional and global LV function. Two-dimensional (2D) speckle tracking imaging (STI) has been used to calculate rotation, but is subject to computational errors due to through plane myocardial motion; 3D STI is not subject to such limitations. We qualitatively evaluated the accuracy of a new 3D wall-motion tracking program (3D-WMT) in terms of physiologically relevant degrees of LV rotation in a digitally controlled phantom.
Methods: Eleven pig hearts with a fixed left ventricular volume of 60mL were passively rotated using a custom apparatus in a water bath. Each heart was mounted on a rotary actuator with the apex externally fixed to optimize the imaging angle and rotated at 0°, 3°, 5°, 7°, 10°, and 15°. Full-volume 3D image loops were acquired on a Toshiba Applio Artida™ ultrasound system. 3D-WMT values were compared to the angle of rotation of the phantom as defined by the actuator.
Results: Linear regression between phantom rotation and 3D-WMT derived values demonstrated a strong correlation as rotation increased (R2 = 0.93, P < 0.001). The mean and standard deviation for 3D-WMT derived rotation for 0° was 0.020° ± 0.016°, 3° was 0.228° ± 0.298°, 5° was 2.073° ± 1.031°, 7° was 4.590° ± 1.391°, 10° was 8.142° ± 1.173°, 12° was 10.289° ± 0.934°, and 15° was 13.059° ± 0.647°. Bland-Altman analysis showed 98% of data points within 95% CI.
Conclusion: The Toshiba 3D-WMT program may be able to track LV rotation at physiologically relevant degrees of rotation.
- © 2013 by American Heart Association, Inc.