Construction of an ultrasound phantom with micrometer-sized wall-less vessels

The development of new ultrasound imaging technologies that aim to resolve objects smaller than the conventional ultrasounds diffraction limit calls for new types of phantoms to evaluate these technologies. When it comes to vascular flow phantoms, this becomes challenging due to the difficulty of manufacturing phantoms with vessels smaller than 1 mm in diameter. Here we describe a novel manufacturing method to construct phantoms with micro-vessels with a size down to 88 μm using oil-based clear ballistic gel (Clear Ballistics, Greenville, SC, USA) as surrounding material. Clear ballistic gel is a long-term stable tissue-mimicking material with speed of sound around 1470 m/s.