Department of Physics, University of Cambridge; Cancer Research UK Cambridge Institute, University of Cambridge.
Ultrasound and Underwater Acoustics Group, Department of Medical, Marine and Nuclear Physics, National Physical Laboratory.
J Vis Exp. 2023 Jun 16(196). doi: 10.3791/65475.
Establishing tissue-mimicking biophotonic phantom materials that provide long-term stability are imperative to enable the comparison of biomedical imaging devices across vendors and institutions, support the development of internationally recognized standards, and assist the clinical translation of novel technologies. Here, a manufacturing process is presented that results in a stable, low-cost, tissue-mimicking copolymer-in-oil material for use in photoacoustic, optical, and ultrasound standardization efforts. The base material consists of mineral oil and a copolymer with defined Chemical Abstract Service (CAS) numbers. The protocol presented here yields a representative material with a speed of sound c(f) = 1,481 ± 0.4 m·s at 5 MHz (corresponds to the speed of sound of water at 20 °C), acoustic attenuation α(f) = 6.1 ± 0.06 dB·cm at 5 MHz, optical absorption µa(λ) = 0.05 ± 0.005 mm at 800 nm, and optical scattering µs'(λ) = 1 ± 0.1 mm at 800 nm. The material allows independent tuning of the acoustic and optical properties by respectively varying the polymer concentration or light scattering (titanium dioxide) and absorbing agents (oil-soluble dye). The fabrication of different phantom designs is displayed and the homogeneity of the resulting test objects is confirmed using photoacoustic imaging. Due to its facile, repeatable fabrication process and durability, as well as its biologically relevant properties, the material recipe has high promise in multimodal acoustic-optical standardization initiatives.
建立提供长期稳定性的组织模拟生物光子体 phantom 材料对于实现跨供应商和机构的生物医学成像设备的比较、支持国际认可标准的发展以及协助新型技术的临床转化至关重要。这里提出了一种制造工艺，可生产出稳定、低成本的组织模拟共聚体-in-oil 材料，用于光声、光学和超声标准化工作。基础材料由矿物油和具有明确化学文摘服务 (Chemical Abstract Service, CAS) 编号的共聚物组成。这里提出的方案可产生具有代表性的材料，其声速 c(f) 在 5 MHz 时为 1,481 ± 0.4 m·s（对应于 20°C 下水的声速），声衰减 α(f) 在 5 MHz 时为 6.1 ± 0.06 dB·cm，在 800nm 时的光学吸收 µa(λ) 为 0.05 ± 0.005 mm，在 800nm 时的光学散射 µs'(λ) 为 1 ± 0.1 mm。该材料可通过分别改变聚合物浓度或光散射（二氧化钛）和吸收剂（油溶性染料）来独立调整声学和光学性能。展示了不同 phantom 设计的制造，并使用光声成像确认了所得测试对象的均匀性。由于其易于重复的制造工艺和耐用性，以及其生物学相关性质，该材料配方在多模态声-光标准化倡议中具有很高的应用前景。
