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, People's Republic of China.
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, People's Republic of China.
Ultrasound Med Biol. 2020 May;46(5):1244-1257. doi: 10.1016/j.ultrasmedbio.2020.01.026. Epub 2020 Feb 26.
Intracerebral hemorrhage is a life-threatening acute cerebrovascular disease characterized by a 30-d mortality rate of 40% and substantial disability for those who survive. The objective of this study is to investigate the feasibility of histotripsy-mediated efficient and fine liquefaction of large-volume hematoma by utilizing a protocol of millisecond-length ultrasound pulse groups combined with fundamental and second harmonic superposition. Experiments were initially performed in an in vitro hematoma phantom, using a two-element confocal-annular array. Results showed that a single ellipsoid shape, histotripsy lesion with major dimensions of 10.8 ± 1.2 mm axially and 4.8 ± 0.2 mm laterally was successfully generated. Controllability of the lesion shape and size could be realized by modulating treatment parameters in single-spot experiments. Large-volume hematomas were efficiently and finely liquefied through multisonications via a treatment strategy under the relatively optimized treatment parameters. Liquefied contents were evacuated and analyzed using a particle sizing system. The size of the lysates for the most part ranged from 4-8 μm, with more than 99% of them being smaller than 10 μm. Experiments were then conducted in an optically transparent tissue phantom to explore the liquefaction mechanisms. The phantom was composed of polyacrylamide hydrogel, embedded with bovine serum albumin (BSA), and a thin phantom layer consisted of red blood cells in the BSA polyacrylamide gel was inlayed in the BSA gel phantom. The related mechanisms, such as the frequent boiling that occurred at multiple positions and the enhanced cavitation, revealed the quick development of the lesion in the phantom and the efficient liquefaction of the clot. These results indicated that the proposed histotripsy approach is feasible for the efficient, precise and fine liquefaction of large-volume hematoma and may be developed as a useful tool for intracerebral hemorrhage treatment.
脑出血是一种危及生命的急性脑血管病，其 30 天死亡率为 40%，幸存者也会有严重残疾。本研究旨在探讨毫秒长超声脉冲群结合基波和二次谐波叠加的方案是否能实现大容量血肿的高效、精细液化。实验最初在体外血肿模型中进行，采用双元共焦环形阵换能器。结果表明，成功产生了单个长轴为 10.8±1.2mm、短轴为 4.8±0.2mm 的椭球形状的 histotripsy 损伤。通过单靶点实验调节治疗参数可以实现损伤形状和大小的可控性。通过多焦点超声处理，在相对优化的治疗参数下，可以高效、精细地液化大容量血肿。使用颗粒粒径分析系统排空并分析液化内容物。裂解物的大部分粒径在 4-8μm 之间，超过 99%的粒径小于 10μm。然后在光学透明组织模型中进行实验，以探索液化机制。该模型由聚丙烯酰胺水凝胶组成，其中嵌入牛血清白蛋白（BSA），并在 BSA 聚丙烯酰胺凝胶中嵌入了一层由 BSA 凝胶中的红细胞组成的薄组织模型。相关机制，如在多个位置发生的频繁沸腾和增强空化，揭示了病变在模型中的快速发展和血凝块的高效液化。这些结果表明，所提出的 histotripsy 方法对于大容量血肿的高效、精确和精细液化是可行的，并且可能被开发为一种用于脑出血治疗的有用工具。
