Multi-Focus Beamforming for Thermal Strain Imaging Using a Single Ultrasound Linear Array Transducer
Man M Nguyen1, Xuan Ding2, Steven A Leers3
1Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA.
Ultrasound in Medicine & Biology
|March 21, 2017
Summary
A novel ultrasound heating design improves thermal strain imaging (TSI) for identifying lipid-rich atherosclerotic plaques. This advancement enhances heating efficiency and area, overcoming key limitations for clinical applications.
Area of Science:
- Biomedical Engineering
- Medical Imaging
- Ultrasound Technology
Background:
- Ultrasound-induced thermal strain imaging (TSI) shows promise for differentiating tissue types in atherosclerotic plaques.
- Clinical translation of TSI is hindered by challenges like motion artifacts, displacement tracking accuracy, limited heating, low signal-to-noise ratio, and small fields of view.
- Existing TSI systems often use separate transducers, leading to bulky setups and difficulties with in vivo operation.
Purpose of the Study:
- To address the limitations in tissue heating for TSI.
- To develop and evaluate a new heating beam design for enhanced heating area and efficiency.
- To facilitate the clinical realization of TSI for plaque characterization.
Main Methods:
- A novel heating beam design was implemented on a clinical linear array imaging transducer.
- In vitro experiments were conducted using tissue-mimicking phantoms and a human carotid endarterectomy sample.
- In silico finite-element simulations were used for comparison with experimental results.
Main Results:
- The new design achieved an effective heating area of approximately 0.85 cm² with a 0.3°C temperature rise in 2 seconds.
- TSI successfully detected a 1 cm lipid-mimicking inclusion within a background, demonstrating a strain contrast of 2.3.
- Lipid-based tissue in a human carotid endarterectomy sample was accurately identified, correlating well with histological findings.
Conclusions:
- The developed heating beam design significantly improves heating capability for TSI.
- This advancement overcomes critical limitations, paving the way for improved in vivo plaque characterization.
- The findings support the potential of this enhanced TSI approach for clinical atherosclerosis assessment.
