title: Minimizing the thermal losses from perfusion during focused ultrasound exposures with flowing microbubbles.
abstract: This paper demonstrated the use of flowing microbubbles (MBs) to minimize thermal losses from perfusion during focused ultrasound exposures due to acoustic cavitation. Temperature and cavitation were simultaneously investigated as MBs flowing through a wall-less flow phantom with varying flow velocities (2-55 cm/s) and concentrations (0%-0.1%) when exposed at different acoustic power levels (5-120 W). The peak temperature at the end of ultrasonic exposures in the flow and in the outer of the vessel as well as the cavitation were higher than those pure controls measured at the same exposure parameters and flow velocities but without MBs. All the peak temperatures initially increased with increasing flow velocities of MBs, followed by a decrease of the peak temperatures with increasing flow velocities when the velocity was higher than the inflection velocity. Meanwhile, cavitation showed a trend of increases with increasing flow velocity. The inflection velocity and cavitation increased with increasing acoustic power and MBs concentration. Thermal lesion appeared around the vessel as MBs flow through the vessel, at which lesion was not observed originally without MBs. These results suggested that this may provide an effective way to minimize thermal losses from perfusion during focused ultrasound exposures.
authors.affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Ding
authors.forename: Mingxi
authors.initials: M
authors.lastname: Wan
authors.forename: Hujie
authors.initials: H
authors.lastname: Jiang
authors.forename: Xu
authors.initials: X
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhong
authors.forename: Supin
authors.initials: S
authors.lastname: Wang
mesh_terms: D000162:Acoustics; D000180:Acrylic Resins; D006358:Hot Temperature; D006801:Humans; D045423:Microbubbles; D019047:Phantoms, Imaging; D014464:Ultrasonic Therapy / Q000379:methods* / Q000592:standards; D014463:Ultrasonography / Q000379:methods* / Q000592:standards; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D000099166:Polyacrylamides