ultrasound scanner
Ultrasound scanner (Foto: iStock)

Based on the same principle as that used by bats to discern shapes depending on the echo of the sound they emit, ultrasound scanners reveal the damage caused to the lungs by Covid-19.

These devices (also known as echographs) emit inaudible sound waves that pass through the skin and are then picked up after they bounce off internal organs in the body.

“So, they display different shades of gray, depending on what the waves are bouncing off, and that’s how you can see inside the body. Ultrasound scanners are machines that allow us to analyze structures within the body,” says Sebastián Rodríguez Llamazares, full professor of respiratory pathologies at the Mexico City campus of Tecnológico de Monterrey, in an interview for Tec Review.


How does it work in detecting Covid-19?

For many decades, lung ultrasound was neglected and rarely used, because air distorted the image and hampered a correct view of various structures at the back of the lungs. However, things have changed.

“The boom in lung ultrasound began twenty years ago, because we started to realize that it could still be used to diagnose illnesses despite all that distortion,” says this Tec academic.

Rodríguez Llamazares explains that the lungs are like a series of little balloons (alveoli) into which the air goes. These are directly connected to a capillary, where the blood passes through and is filled with oxygen.

“There’s an area of tissue between the capillary and the alveoli called the interstitium. Covid-19, like many other diseases, inflames the interstitium and thickens it, so the distance between the alveoli and the capillary increases, making the oxygen have to travel further to reach the blood. This is the reason why Covid-19 pneumonia reduces the available oxygen. With this in mind, when an ultrasound is performed on a patient with Covid-19 pneumonia, we see interstitial thickening,” the expert explains.

We can also look at the state of the lungs through tomography. However, with the saturation of health services, this takes longer than ultrasound.

“Ultrasound is easy to use and doesn’t require sending the patient to a special laboratory, as tomography does. It’s useful in Covid cases, because when patients arrive in the emergency area, it allows us to assess whether or not they have pneumonia. Once they’re hospitalized, it’s extremely useful in managing critical conditions, because it makes it possible to assess internal aspects of patients’ bodies,” states the professor of respiratory pathologies.

Lung ultrasound doesn’t require bulky equipment, unlike that used during pregnancy. According to Rodríguez, hospitals tend to use portable ultrasound scanners to examine the lungs.

A gadget with an integrated digital platform

What Rodríguez says is confirmed by Miguel Ángel Corona Franco, an ultrasound product and clinical applications specialist at Philips Healthcare Mexico. In an interview for Tec Review, he says that the portable ultrasound scanner is a very versatile solution whose technology enables it to be used in places where quick and easy access to ultrasound images is required for diagnosis.

“It also makes it easier for the patient to have a quick diagnosis, to be able to refer them to another more specialized area of attention if needed,” he says.

What’s more, Corona Franco says that Philips has developed portable ultrasound scanners that are compatible with digital platforms and allow doctors to collaborate remotely by sharing ultrasound images in real time and through video calls.

He also tells us that because portable ultrasound scanners are small, they can be easily decontaminated, since they consist of a mobile device (a smartphone or a tablet) and the transducer with its cable, allowing almost immediate continuity to study other patients.

“This is a great advantage, because tomography, the other imaging technique for lung diagnosis, is ionizing, and also involves decontaminating the tomography room after conducting a study on each patient,” he concludes.


TAGS: lungs, hospital, pneumonia