title: Thermal safety simulations of transient temperature rise during acoustic radiation force-based ultrasound elastography.
abstract: Ultrasound transient elastography is a new diagnostic imaging technique that uses acoustic radiation force to produce motion in solid tissue via a high-intensity, long-duration "push" beam. In our previous work, we developed analytical models for calculating transient temperature rise, both in soft tissue and at a bone/soft tissue interface, during a single acoustic radiation force impulse (ARFI) imaging frame. The present study expands on these temperature rise calculations, providing applicable range assessment and error analysis for a single ARFI frame. Furthermore, a "virtual source" approach is described for temperature and thermal dose calculation under multiple ARFI frames. By use of this method, the effect of inter-frame cooling duration on temperature prediction is analyzed, and a thermal buildup phenomenon is revealed. Thermal safety assessment indicates that the thermal dose values, especially at the absorptive bone/soft tissue interface, could approach recommended dose thresholds if the cooling interval of multiple-frame ARFI elastography is too short.
authors.affiliation: Center for Devices and Radiologic Health, Office of Medical Products and Tobacco, Food and Drug Administration, Silver Spring, Maryland, USA. Electronic address: yunbo.liu@fda.hhs.gov.
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Center for Devices and Radiologic Health, Office of Medical Products and Tobacco, Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Herman
authors.affiliation: Center for Devices and Radiologic Health, Office of Medical Products and Tobacco, Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Joshua E
authors.initials: JE
authors.lastname: Soneson
authors.affiliation: Center for Devices and Radiologic Health, Office of Medical Products and Tobacco, Food and Drug Administration, Silver Spring, Maryland, USA.
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Harris
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006358:Hot Temperature; D008954:Models, Biological; D015203:Reproducibility of Results; D012449:Safety / Q000706:statistics & numerical data*; D013814:Thermal Conductivity
keywords: Acoustic output; Acoustic radiation force impulse; Exposure regulation; Radiation force elastography; Transient temperature rise; Ultrasonic heating