Abstract 8987: Strain Determination by a High Resolution DENSE 3D Speckle Tracking Method Using a New Nongated 4D Echo Image Loops: Validation Against Sonomicrometry
Background: We tested our DENSE 3D speckle tracking method for strain computation on new nongated 4D echocardiography images, which is a significant resource for 3D imaging of fetal hearts without requiring EKG gating.
Methods: We studied freshly harvested rabbit hearts (n=5) due to their smaller size, in a water tank to facilitate ultrasound scanning. Each heart was connected to a calibrated pulsatile pump through a latex balloon in the LV cavity secured at the mitral annulus. Two 0.7mm sonomicrometry crystals were secured into myocardium along the long axis of the LV. Pulsatile heart motion was generated by injecting 5 different stroke volumes (SV; 1,2,3,4 and 5ml) into the LV with the calibrated pump. At each SV, sonomicrometry displacement data was recorded and 4D images acquired with an X6-1probe on a Philips iU22 ultrasound system. Image data was exported in AVS format and processed in our MatLab based DENSE speckle tracking method for strain computation.
Results: Increasing SV increased stretching of myocardial tissue which was detected as well as correlated increases in longitudinal strain both by sonomicrometry and the DENSE speckle tracking strain method. Sonomicrometry derived strains showed a good correlation with 3D DENSE derived strains at all SVs studied (r=0.85, p<0.05).
Conclusions: New nongated 4D echocardiography is feasible for strain determination in imaging of small hearts.
- © 2012 by American Heart Association, Inc.