Bandpass sampling of high-frequency tissue motion
Hani Eskandari1, Orcun Goksel, Septimiu E Salcudean
1Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, Canada. hanie@ece.ubc.ca
Summary
Bandpass sampling enables high-frequency ultrasound elastography by allowing tissue motion to be accurately measured at lower sampling rates. This technique simplifies dynamic elastography, improving tissue property characterization.
Area of Science:
- Biomedical Engineering
- Medical Imaging
- Ultrasound Technology
Background:
- Characterizing tissue viscoelasticity necessitates measuring motion at frequencies beyond conventional ultrasound frame rates.
- Existing methods face limitations due to high-frequency sampling requirements.
Purpose of the Study:
- To introduce and validate bandpass sampling for high-frequency tissue motion measurement in ultrasound elastography.
- To demonstrate the feasibility of using conventional ultrasound systems for dynamic elastography.
Main Methods:
- Applied bandpass sampling to tissue motion analysis, enabling reconstruction of high-frequency signals at lower sampling rates.
- Utilized finite element method and ultrasound simulations for validation.
- Conducted experiments on tissue-mimicking materials to assess motion estimation accuracy.
Main Results:
- Accurate motion estimation was achieved using a sampling rate below the Nyquist rate.
- Elasticity and viscosity were successfully measured in a phantom, delineating an inclusion.
- Bandpass sampling allows high-frequency dynamic elastography with conventional ultrasound beamforming.
Conclusions:
- Bandpass sampling is a viable technique for high-frequency ultrasound elastography.
- The method simplifies implementation by avoiding beam interleaving or extra hardware.
- Enables advanced tissue property characterization using standard diagnostic ultrasound systems.
