Seismic technology to probe the Earth adapted to probe the brain

Tuesday, May 26th, 2020

For decades, geologists have used sound waves travelling through the Earth to search for oil, image fault lines and attempt to predict earthquakes:

But in recent years seismology has been supercharged by a computational technique called full waveform inversion (FWI), which uses complex computer algorithms to scavenge ever more information from seismic data, and make much more detailed and accurate 3D maps of the Earth’s crust.

Now scientists at Imperial College London have adapted the same technology into a prototype head-mounted scanner that produced imaging information they say could be used in the future to produce high-resolution 3D images of the brain.

synthesized-wavefield-crossing-the-head

The device uses a helmet fitted with an array of acoustic transducers that act as both sound transmitters and receivers. The system uses low frequency sound waves that are able to penetrate the skull and pass through the brain without harming brain tissue. The sound waves are altered as they pass through different brain structures, then the signals are read and run through the FWI algorithm. In simulations the team got results that make them confident they can produce high-resolution 3D images that may be as good, if not better, than more traditional approaches.

Such a device, because of its simplicity and presumably lower cost, could make brain imaging much more widely available.

If developed into a small, portable version, it could have a powerful impact on the diagnosis of brain injury. For example, doctors in emergency rooms or paramedics would be able to do instant brain scans of accident victims with head injuries, or stroke victims.

Current brain scanning technology is very expensive so its use is effectively rationed, with long wait times for non-emergency appointments. It’s also cumbersome, not very well suited to some emergency situations, and can’t be used on some patients. MRI, for example, can’t be used on patients with metallic medical implants or victims of accidents who might have metallic foreign bodies in them. They’re also huge, loud and confining, which can be a big issue for some patients.

Leave a Reply