Cardiac biplane strain imaging: initial in vivo experience

Area of Science:

• Biomedical Engineering
• Cardiovascular Imaging
• Medical Ultrasound

Background:

• Congenital heart disease requires advanced imaging for monitoring cardiac function.
• Assessing myocardial strain in multiple directions is crucial for understanding cardiac pathologies.
• Existing ultrasound techniques may have limitations in capturing comprehensive cardiac strain data.

Purpose of the Study:

• To propose and validate a biplane strain imaging method for simultaneous, multi-directional cardiac strain estimation.
• To utilize a novel animal model simulating pediatric congenital heart disease for in vivo testing.
• To establish a framework for monitoring cardiac hypertrophy and fibrosis development.

Main Methods:

• Employed a commercial ultrasound system with radio frequency (RF) data processing for 2D strain estimation.
• Utilized biplane image acquisition at a frame rate below 100 Hz.
• Tested the method in vivo on a canine model with induced aortic stenosis.

Main Results:

• Demonstrated feasibility of measuring radial, circumferential, and longitudinal strain up to 70% at 100 Hz.
• Showed excellent correlation between strain curves from perpendicular planes.
• Confirmed feasibility and reproducibility of simultaneous multi-directional strain assessment.
• Observed decreased strain (rate) with increasing valvular stenosis, correlating with histological findings of fibrosis.

Conclusions:

• The biplane strain imaging method is feasible and reproducible for assessing multi-directional cardiac strain.
• This technique provides a valuable framework for monitoring cardiac hypertrophy and fibrosis in congenital heart disease models.
• Findings support the use of this method for quantitative assessment of cardiac mechanical function in disease states.