In Vitro and In Vivo Investigation of High-Intensity Focused Ultrasound (HIFU) Hat-Type Ablation Mode
Hongya Dai, Fei Chen, Sijing Yan, Xiaoya Ding, Dazhao Ma, Jing Wen, Die Xu, Jianzhong Zou
College of Biomedical Engineering, Chongqing Medical University, State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and The Ministry of Science and Technology, Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing, China (mainland)
Med Sci Monit 2017; 23:3373-3382
The aim of this study was to investigate the feasibility of the application of high-intensity focused ultrasound (HIFU) hat-type ablation mode in in vitro and in vivo models, and to compare the ablation effects of different parameter combinations.
MATERIAL AND METHODS: HIFU hat-type ablation was performed in isolated bovine liver tissue and in the liver tissue in living rabbits, and the coagulative necrosis for different parameter combinations (plane angles and irradiation order) was investigated. We also analyzed and compared the ablation effects of traditional ablation and hat-type ablation modes. Coagulative necrosis morphology was detected with TTC staining, and the coagulative necrosis volume and energy efficiency factor (EEF) were calculated and compared.
RESULTS: Coagulative necrosis was observed in all the ablated groups, and the coagulative necrosis volume was much larger than the irradiation area. The coagulative necrosis induced by the hat-type ablation was more regular and controllable than the traditional ablation. The angles between the ablation planes determined the coagulative necrosis morphology, but did not affect the coagulative necrosis volume. Moreover, the irradiation order significantly influenced the coagulative necrosis. Importantly, under certain conditions, hat-type ablation achieved higher efficiency compared with the traditional ablation mode.
CONCLUSIONS: Compared with the traditional ablation mode, HIFU hat-type ablation effectively shortened the irradiation time, reduced the over-accumulation of energy, and increased the HIFU ablation efficiency.
Keywords: Ablation Techniques, High-Intensity Focused Ultrasound Ablation, in vitro