Cardiovascular angiography using liquid metal

Understanding the fine structure of the blood vessels of the heart and other organs is the direction that surgeons and anatomists will continue to explore. Although traditional imaging techniques can clearly show the structure of large blood vessels, it is difficult for small blood vessels. A conventional way would be tomography through X-rays to create a refined blood vessel model. However, to achieve this operation, the blood vessels must be filled with contrast agents, whereas the amount of conventional contrast agents entering the small blood vessels is extremely limited.


At present, two researchers at Tsinghua University in Beijing have created a new contrast agent that uses liquid metal to fill blood vessels. The traditional contrast agent is based on iodine because it has a high electron density and can absorb X-rays. However, there is a more efficient way to absorb X-rays, that is, use denser fluids. But no one has tried it until now. The new solution is to use liquid metal. The two researchers tried to use helium for contrast imaging. The melting point of the metal helium is about 29 degrees Celsius and therefore it is liquid at body temperature. In addition, osmium has a good chemical stability, does not react with water at this temperature, and therefore can flow in blood vessels. They injected liquid metal into the pig's heart and performed an X-ray.
The results show that the hemorrhoids show the blood vessels clearly enough. The technique can even show capillaries with a diameter of only 0.07 mm. These capillaries were barely detectable before, but they are now clearly displayed on the images. This technology has great potential for three-dimensional imaging of organs. For human trials, the two are optimistic. They said that wolfberry is chemically inert and non-toxic to humans. A small amount of metal is injected into the blood vessel and can be removed later without leaving a residue. Of course, this needs to be verified through previous experiments. If it is successful, this will bring a huge breakthrough to human imaging technology.