Acoustic Radiation Force Impulse (ARFI) Imaging: a Review

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Acoustics

Background:

• Traditional ultrasonic elasticity imaging relies on transducer compression, leading to operator dependency.
• Acoustic radiation force techniques bypass the need for compression, offering improved consistency.
• Impulsive, harmonic, and steady-state radiation force excitations are established methods.

Purpose of the Study:

• To review acoustic radiation force-based elasticity imaging methods.
• To compare Acoustic Radiation Force Impulse (ARFI) and Shear Wave Elasticity Imaging (SWEI) approaches.
• To present clinical applications of these novel imaging techniques.

Main Methods:

• Utilizing impulsive acoustic radiation force excitation (< 1 ms).
• Employing ARFI imaging to visualize relative tissue stiffness differences within the excitation region.
• Using SWEI to quantify tissue stiffness by monitoring shear wave propagation speed.

Main Results:

• ARFI imaging provides high-resolution, high-contrast images comparable to B-mode.
• SWEI offers quantitative stiffness measurements, albeit with lower spatial resolution.
• Tissue stiffness correlates inversely with displacement and shear wave speed.

Conclusions:

• Acoustic radiation force methods, including ARFI and SWEI, are promising for non-invasive elasticity assessment.
• These techniques provide complementary information for enhanced diagnostic capabilities.
• Clinical applications demonstrate the potential of these advanced ultrasound elasticity imaging methods.