Estimation of radial strain and rotation using a new algorithm based on speckle tracking.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Cardiovascular Mechanics

Background:

• Lagrangian strain (LS) and local rotation (ROT) are crucial biomechanical parameters.
• Accurate measurement of LS and ROT is essential for understanding tissue mechanics.
• Current methods may have limitations in spatial resolution or angle independence.

Purpose of the Study:

• To evaluate a novel algorithm for point-to-point Lagrangian strain (LS) measurement.
• To assess the accuracy of a new algorithm for local rotation (ROT) estimation.
• To determine if speckle tracking (SpT) can reliably measure LS and ROT without border detection.

Main Methods:

• Two dynamic phantoms were scanned at various frame rates (30, 60, 90 Hz).
• Lagrangian strain (LS) was measured using SpT and compared to sonomicrometer (SN-LS) measurements.
• Local rotation (ROT) was estimated using SpT and compared to computed tomography (CT) derived measurements.

Main Results:

• SpT-derived LS strongly correlated with sonomicrometer-measured LS across all tested frame rates (R² ≥ 0.98).
• SpT-derived ROT showed significant correlation with CT-derived ROT at all frame rates (R² ≥ 0.95).
• High accuracy was maintained irrespective of the frame rate.

Conclusions:

• Point-to-point SpT enables accurate measurement of LS between distinct tissue regions.
• SpT facilitates reliable estimation of ROT in specific tissue areas.
• The novel algorithm offers angle-independent, high-resolution LS and ROT quantification without border detection.