Cabrelli Luciana C, Grillo Felipe W, Sampaio Diego R T, Carneiro Antonio A O, Pavan Theo Z
Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
Ultrasound Med Biol. 2017 Sep;43(9):2086-2094. doi: 10.1016/j.ultrasmedbio.2017.05.010. Epub 2017 Jun 23.
Phantoms are important tools for image quality control and medical training. Many phantom materials have been proposed for ultrasound; most of them use water as the solvent, but these materials have disadvantages such as dehydration and low temporal stability if not properly stored. To overcome these difficulties, copolymer-in-oil gel was proposed as an inert and stable material; however, speed of sound for these materials is still lower than what is described for most biological tissues. Here, we propose the glycerol dispersion in oil-based gels to modify the acoustic and elastic properties of copolymer-in-oil phantoms. We manufactured copolymer-in-oil gels using styrene-ethylene/butylene-styrene (SEBS) in concentrations 8%-15%. We used 2 types of mineral oils with different viscosities. Glycerol was added in a volume fraction 0%-30% of the total amount of liquid. The acoustic (i.e., speed of sound, attenuation and backscattering) and the mechanical (i.e., density and Young's modulus) properties of the samples were within the range of values observed for soft tissues. The acoustic parameters of the samples were dependent on oil viscosity and glycerol concentration. The speed of sound ranged 1423 m/s - 1502 m/s, while the acoustic attenuation and the ultrasonic backscattering increased by adding glycerol. The density and the Young's moduli were less affected by the presence of glycerol. We conclude that glycerol can be used to control the acoustic parameters of copolymer-in-oil gels. Additionally, it opens the possibility of incorporating other oil-insoluble substances to control further properties of the phantom.
体模是图像质量控制和医学培训的重要工具。已经提出了许多用于超声检查的体模材料；其中大多数使用水作为溶剂，但如果储存不当，这些材料存在诸如脱水和时间稳定性低等缺点。为克服这些困难，提出了油包共聚物凝胶作为一种惰性且稳定的材料；然而，这些材料的声速仍低于大多数生物组织的声速。在此，我们提出在油基凝胶中分散甘油以改变油包共聚物体模的声学和弹性特性。我们使用浓度为8% - 15%的苯乙烯 - 乙烯/丁烯 - 苯乙烯（SEBS）制造油包共聚物凝胶。我们使用了两种具有不同粘度的矿物油。甘油的添加量占液体总量的体积分数为0% - 30%。样品的声学特性（即声速、衰减和后向散射）和力学特性（即密度和杨氏模量）在软组织观察到的值范围内。样品的声学参数取决于油的粘度和甘油浓度。声速范围为1423米/秒 - 1502米/秒，而添加甘油后声学衰减和超声后向散射增加。甘油的存在对密度和杨氏模量的影响较小。我们得出结论，甘油可用于控制油包共聚物凝胶的声学参数。此外，它还为加入其他油不溶性物质以控制体模的进一步特性提供了可能性。
