There are better ways to shake up your brain (Image: Federica Rainò/Getty)

Your brain is buzzing. Analysing those natural vibrations might help spot tumours and other abnormalities, and now an algorithm normally used to study earthquakes has been adapted to do just that.

The elasticity of different parts of the body is a useful way to tell if something is wrong. Lumps can be a sign of cancer, of course, and stiffness in certain organs can indicate disease. Ultrasound scans that measure the elasticity of the liver, for example, can show up cirrhosis.


It is more difficult to measure the elasticity of the brain. Ultrasound isn’t an option, because it can’t pass through the skull. Doctors are limited to touching the brain directly when a section of the skull has been removed during surgery. “Doctors can only feel a few centimetres deep, so only have information about the elasticity of the surface of the brain,” says Stefan Catheline at INSERM in Paris, France.

Catheline’s team, and others around the world, have been working on a way to use modified MRI scanners to measure brain elasticity. MRI usually works by measuring water content, but with modification it can be made to measure the movement of water molecules. This allows them to pick up on movements in tissues when they are shaken up.

Shake it up

But such devices haven’t made it to the clinic yet, in part because they aren’t very comfortable to use, says Catheline. “It’s not pleasant,” he says. “It is also difficult to shake the entire skull using a vibrator.” Some teams have tried using vibrating teeth moulds, which have given participants headaches. More recently groups have developed vibrating pillows.

Now Catheline is trying another approach. Instead of physically shaking the head, why not simply take advantage of the brain’s natural vibrations? “We tend to think of the brain as a static organ, but there is a lot of movement,” he says. “When blood is pumped into the brain it pulsates, and induces vibrations.”

The idea came to Catheline after he spent time working with seismologists, who study how to extract information from the seismic waves created by earthquakes. He borrowed the algorithm his colleagues used to analyse the Earth’s vibrations, and incorporated it into his modified MRI scanner. As a result, his team were able to measure the natural vibrations in the brains of two healthy volunteers – information normally dismissed as “noise”.

The body’s noise

“It is an intriguing approach,” says Armando Manduca at the Mayo Clinic in Rochester, Minnesota. “There could potentially be great value in using what has been considered the body’s noise, which is usually seen as a problem.”

Such scans will be able to reveal a lot more information about what’s going on in the brain than traditional MRI scans, says Neil Roberts at the University of Edinburgh, UK. The water content of our cells doesn’t tend to vary much, but the mechanical properties do. So while a bit of brain tissue might look like it’s made up of identical cells on an MRI, an elastography scan could reveal huge variation in stretchiness, hardness or gloopiness. “Being able to essentially touch inside the brain is going to be much more discriminatory than conventional MRI,” he says. “It opens up a rich world for study and diagnosis.”

Catheline hopes his technique will eventually help doctors diagnose diseases and monitor the success of their treatment. The plaques found in some forms of dementia, for example, have more elasticity than normal brain tissue – the new technique might be able to detect those differences.

Manduca thinks that the first clinical application will probably be to assess the hardness of an existing tumour. This can be useful before surgery, he says: while a soft mass can be swiftly sucked away, harder tumours must be painstakingly dissected out, sometimes taking several hours. Such applications are probably still a few years away, he adds.

Journal reference: PNAS, DOI: 10.1073/pnas.1509895112