Key Points
- To develop and validate a noninvasive ultrasound tracking method capable of accurately measuring depth-resolved myocardial wall velocity and thickening during cardiac cycles.
- Developed an acoustic tracking technique to detect low-amplitude (<10 µm) high-frequency wall velocity signals superimposed on large (10 mm) cardiac displacements across frequencies up to several hundred Hertz.
- Sampled multiple points across the left ventricular wall depth to separate global wall motion from local layer thickening and thinning during contraction and relaxation.
- Superimposed color-coded myocardial strain components onto M-mode ultrasound images (red for contraction, blue for expansion) and evaluated the system in preliminary human tests.
- Successfully tracked micro-scale heart wall velocities with high reproducibility across frequencies up to several hundred Hertz continuously over approximately 10 heartbeats.
- Verified the experimental principle of separating global cardiac motion from depth-dependent layer thickening and identified the specific acoustic frequency bands associated with myocardial motility.
Structured PICO
PPopulationHuman subjects in preliminary studies
IInterventionNew ultrasound-based method for tracking heart wall movement and color-coded imaging of local myocardial thickening
OOutcomeVerification of the method's principle and identification of the frequency band of components generated by myocardial thickening/thinningsurrogate
A novel ultrasound-based method successfully tracks and color-codes local myocardial thickening, offering potential for detailed noninvasive assessment of myocardial layer function.