Cavitation enhances coagulated size during pulsed high-intensity focussed ultrasound ablation in an isolated liver perfusion system. (3rd April 2017)

• Record Type: Journal Article
• Authors: Zhao, Lu-Yan; Liu, Shan; Chen, Zong-Gui; Zou, Jian-Zhong; Wu, Feng
• Is Part Of: International journal of hyperthermia. Volume 33:Number 3(2017)
• Page Start: 343
• Page End: 353
• Publication Date: 2017-04-03
• Subjects: Cavitation -- high-intensity focused -- focussed ultrasound -- perfusion flow rate -- porcine liver perfusion -- thermal ablation; Thermotherapy -- Periodicals; 615.832
• DOI: 10.1080/02656736.2016.1255918
• Languages: English
• ISSNs: 0265-6736

Abstract

Abstract: Purpose: To investigate whether cavitation enhances the degree of coagulation during pulsed high-intensity focussed ultrasound (HIFU) in an isolated liver perfusion system. Methods: Isolated liver was treated by pulsed HIFU or continuous-wave HIFU with different portal vein flow rates. The cavitation emission during exposure was recorded, and real-time ultrasound images were used to observe changes in the grey scale. The coagulation size was measured and calculated. Results: HIFU treatment led to complete coagulation necrosis and total cell destruction in the target regions. Compared to exposure at a duty cycle (DC) of 100%, the mean volumes of lesions induced by 6 s exposure at DCs of 50% and 10% were significantly larger ( P < . 01) but were smaller at a DC of 5%. The necrosis volume was negatively related to the perfusion rate in the pulsed HIFU at a DC of 50% for exposure durations of 4 and 6 s, while the perfusion flow rate did not affect the necrosis volume for exposure durations of 1, 2 and 3 s. For increased perfusion flow rates, there was no significant decrease in the cavitation activity for the pulsed-HIFU ( P > .05). For continuous-wave HIFU exposure, there was a significant decrease in the necrosis volume and cavitation activity for exposure times of 1, 2, 3, 4, and 6 s with increasing portal perfusion rates. Conclusion: Perfusion flow rates negatively influence cavitation activity and coagulation volume. Ablation is significantly enhanced during pulsed HIFU exposure compared with continuous-wave HIFU.