Laser-enhanced high-intensity focused ultrasound heating in an in vivo small animal model

The enhancedheatingeffect during the combination of high-intensity focused ultrasound (HIFU) and low-optical-fluence laserillumination was investigated by using anin vivo murine animal model. The thighs of murine animals were synergisticallyirradiated by HIFU and pulsed nano-second laser light. Thetemperature increases in the target region weremeasured by a thermocouple under different HIFUpressures, which were 6.2, 7.9, and 9.8  MPa, in combination with 20 mJ/cm2 laser exposures at 532  nm wavelength. In comparison with conventional laser therapies, the laser fluence used here is at least one order of magnitude lower. The results showed that laserillumination could enhancetemperature during HIFU applications. Additionally,cavitation activity was enhanced when laser and HIFUirradiation were concurrently used. Further, a theoretical simulation showed that the inertialcavitation threshold was indeed decreased when laser and HIFUirradiation were utilized concurrently.
Source: Applied Physics Letters - Category: Physics Authors: Source Type: research