La Jornada: Scientists develop blood-like liquid to calibrate ultrasounds

A research group in which the Institute of Physics of the National Autonomous University of Mexico (IFUNAM) participated developed a liquid with properties very similar to blood, useful for calibrating ultrasounds – a key tool that measures blood flow to detect problems in the heart or the development of tumors – and guarantee accurate measurements.

“We wanted to make a material that had acoustic properties similar to those of blood for use in flow phantoms, devices in which blood circulation is simulated to evaluate the performance of ultrasound equipment. doppler or vascular without using patients,” comments Lizbeth Ayala Domínguez, IFUNAM researcher.

The first time Ayala Domínguez worked on the subject was during his stay at the University of Wisconsin-Madison. Once he entered the Institute of Physics, he decided to return to the topic with his students and new materials.

“There was already a formulation with different components: water, glycerol, dextran, a surfactant and nylon particles, which is the main component used to simulate red blood cells.”

Because some of the materials in the original recipe are no longer sold, such as the Simperonic N surfactant, they were replaced by others and, after a dozen tests with various combinations and concentrations, they obtained three formulations: one with a viscosity similar to blood, another slightly more viscous and one less viscous.

“The most difficult thing was to achieve a stable fluid, because the particles tend to settle or float, which generates incorrect measurements.”

After eight months of work, they achieved a formula that had the right stability, density and acoustic properties. The next step was to test it on medical equipment such as doppler and vascular ultrasound, where it demonstrated its effectiveness.

Furthermore, when compared with artificial blood from a German laboratory, better values ​​of sound speed, viscosity and density were observed.

This advance reveals that the calibrators available on the market can be improved, “which impacts the quality of the measurements and, therefore, the diagnosis of diseases.”

Auxiliary for early diagnosis of diseases

Ayala Domínguez explains that the growth of tumors is linked to the formation of new blood vessels. When they are small, they receive oxygen and nutrients without problem, but as they increase in size, they develop their own vascular network to survive.

“In tumors like breast cancer, there is a stage in which they have not yet developed vessels, but then they begin to do so. And what would be ideal for us with ultrasound? Detect them at that moment.”

Having well-calibrated equipment would allow these changes to be identified in early stages and the treatment to be more precisely defined according to the stage of the tumor.

“As medical physicists, we seek to help doctors know how reliable equipment is in diagnosing diseases,” he adds.

Currently, the team is working on the development of a flow phantom to evaluate ultrasound doppler and high resolution applied in breast cancer studies.

If we take into account that cancer is a disease that has a high incidence in Mexico, improving early diagnosis methods significantly increases patients’ chances of recovery.

Ayala Domínguez called on young people to come to the area, “we need more medical physicists, not only in hospitals, but also in the laboratory.”