Design and Characterization of an Acoustically and Structurally Matched 3-D-Printed Model for Transcranial Ultrasound Imaging
Design and Characterization of an Acoustically and Structurally Matched 3-D-Printed Model for Transcranial Ultrasound Imaging
复制标题
用于经颅超声成像的声学和结构匹配的 3D 打印模型的设计和表征
DOI：
10.1109/tuffc.2018.2811756
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发表时间：
2018-05-01
影响因子：
3.6
通讯作者：
Wan, Mingxi
中科院分区：
文献类型：
--
作者：
Bai, Chen;Ji, Meiling;Wan, Mingxi
为了研究通过颞骨的人类经颅超声成像（TUI），需要完整的人类颅骨。由于获得头骨复杂且昂贵，因此需要在不切除或磨损头骨的情况下进行实验。此外，为了模拟血管目标的血液循环，纤维素管通常适合具有直线特征的血管模拟。这些限制实验研究的问题可以通过设计一个具有声学和尺寸特性的3D打印头骨模型来克服，该模型与真实的头骨和具有曲线和分叉的血管模型相匹配。首先，在2-MHz频率下识别在声衰减系数和声传播速度方面与真实的头骨匹配的最佳打印材料，即，7.06颅骨的平均速度分别为2168.71m/s和6.98dB/mm，而印刷材料的平均速度分别为2114.72m/s和6.98dB/mm。模型制作完成后，打印颅骨的颞骨平均厚度约为1.8 mm，而真实的颅骨的颞骨平均厚度为1.7 mm。然后，用3D打印的低声衰减（0.6 dB/mm）血管设计了血管体模。它被一个透明的聚丙烯酰胺凝胶中的猪脑组织覆盖。在声学一致性表征后，基于设计的颅骨模型和血管体模，通过低频分辨率增强成像区分内径为1和0.7 mm的血管。测量和成像结果证明该模型和体模是真实且可行的替代方案，并且将对TUI、高强度聚焦超声或其他治疗研究产生兴趣。
For investigating human transcranial ultrasound imaging (TUI) through the temporal bone, an intact human skull is needed. Since it is complex and expensive to obtain one, it requires that experiments are performed without excision or abrasion of the skull. Besides, to mimic blood circulation for the vessel target, cellulose tubes generally fit the vessel simulation with straight linear features. These issues, which limit experimental studies, can be overcome by designing a 3-D-printed skull model with acoustic and dimensional properties that match a real skull and a vessel model with curve and bifurcation. First, the optimal printing material which matched a real skull in terms of the acoustic attenuation coefficient and sound propagation velocity was identified at 2-MHz frequency, i.e., 7.06 dB/mm and 2168.71 m/s for the skull while 6.98 dB/mm and 2114.72 m/s for the printed material, respectively. After modeling, the average thickness of the temporal bone in the printed skull was about 1.8 mm, while it was to 1.7 mm in the real skull. Then, a vascular phantom was designed with 3-D-printed vessels of low acoustic attenuation (0.6 dB/mm). It was covered with a porcine brain tissue contained within a transparent polyacrylamide gel. After characterizing the acoustic consistency, based on the designed skull model and vascular phantom, vessels with inner diameters of 1 and 0.7 mm were distinguished by resolution enhanced imaging with low frequency. Measurements and imaging results proved that the model and phantom are authentic and viable alternatives, and will be of interest for TUI, high intensity focused ultrasound, or other therapy studies.