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On the thermal effects associated with radiation force imaging of soft tissue.
- Source :
-
IEEE transactions on ultrasonics, ferroelectrics, and frequency control [IEEE Trans Ultrason Ferroelectr Freq Control] 2004 May; Vol. 51 (5), pp. 551-65. - Publication Year :
- 2004
-
Abstract
- Several laboratories are investigating the use of acoustic radiation force to image the mechanical properties of tissue. Acoustic Radiation Force Impulse (ARFI) imaging is one approach that uses brief, high-intensity, focused ultrasound pulses to generate radiation force in tissue. This radiation force generates tissue displacements that are tracked using conventional correlation-based ultrasound methods. The tissue response provides a mechanism to discern mechanical properties of the tissue. The acoustic energy that is absorbed by tissue generates radiation force and tissue heating. A finite element methods model of acoustic heating has been developed that models the thermal response of different tissues during short duration radiation force application. The beam sequences and focal configurations used during ARFI imaging are modeled herein; the results of these thermal models can be extended to the heating due to absorption associated with other radiation force-based imaging modalities. ARFI-induced thermal diffusivity patterns are functions of the transducer f-number, the tissue absorption, and the temporal and spatial spacing of adjacent ARFI interrogations. Cooling time constants are on the order of several seconds. Tissue displacement due to thermal expansion is negligible for ARFI imaging. Changes in sound speed due to temperature changes can be appreciable. These thermal models demonstrate that ARFI imaging of soft tissue is safe, although thermal response must be monitored when ARFI beam sequences are being developed.
- Subjects :
- Animals
Computer Simulation
Connective Tissue diagnostic imaging
Dose-Response Relationship, Radiation
Elasticity
Finite Element Analysis
Hot Temperature
Humans
Radiation Dosage
Thermal Conductivity
Thermography methods
Ultrasonics
Ultrasonography
Body Temperature physiology
Body Temperature radiation effects
Connective Tissue physiology
Connective Tissue radiation effects
Energy Transfer physiology
Models, Biological
Subjects
Details
- Language :
- English
- ISSN :
- 0885-3010
- Volume :
- 51
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- IEEE transactions on ultrasonics, ferroelectrics, and frequency control
- Publication Type :
- Academic Journal
- Accession number :
- 15217233