There are better ways to shake up your brain (Image: Federica Rain貌/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.
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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 , for example, can show up cirrhosis.
It is more difficult to measure the elasticity of the brain. Ultrasound isn鈥檛 an option, because it can鈥檛 pass through the skull. Doctors are limited to touching the brain directly when a section of the skull has been removed during surgery. 鈥淒octors can only feel a few centimetres deep, so only have information about the elasticity of the surface of the brain,鈥� says at INSERM in Paris, France.
Catheline鈥檚 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鈥檛 made it to the clinic yet, in part because they aren鈥檛 very comfortable to use, says Catheline. 鈥淚t鈥檚 not pleasant,鈥� he says. 鈥淚t is also difficult to shake the entire skull using a vibrator.鈥� 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鈥檚 natural vibrations? 鈥淲e tend to think of the brain as a static organ, but there is a lot of movement,鈥� he says. 鈥淲hen blood is pumped into the brain it pulsates, and induces vibrations.鈥�
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鈥檚 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 鈥� information normally dismissed as 鈥渘oise鈥�.
The body鈥檚 noise
鈥淚t is an intriguing approach,鈥� says at the Mayo Clinic in Rochester, Minnesota. 鈥淭here could potentially be great value in using what has been considered the body鈥檚 noise, which is usually seen as a problem.鈥�
Such scans will be able to reveal a lot more information about what鈥檚 going on in the brain than traditional MRI scans, says at the University of Edinburgh, UK. The water content of our cells doesn鈥檛 tend to vary much, but the mechanical properties do. So while a bit of brain tissue might look like it鈥檚 made up of identical cells on an MRI, an elastography scan could reveal huge variation in stretchiness, hardness or gloopiness. 鈥淏eing able to essentially touch inside the brain is going to be much more discriminatory than conventional MRI,鈥� he says. 鈥淚t opens up a rich world for study and diagnosis.鈥�
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, 鈥� 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,
