From his base at the Washington University in St. Louis, Lihong Wang is carrying out some pretty amazing work. Specialising in creating futuristic medical technology, he’s already been involved in developing instruments to detect individual cancer cells in the bloodstream, a camera that can shoot at 100 billion frames per second, and equipment capable of detecting oxygen consumption deep in the body.
Wang, a professor of biomedical engineering, sees it as simply turning ideas that were once deemed to be science fiction, into science fact, and his ultimate goal is to combine light and sound to unlock the mysteries in the human brain. However, finding out how we learn, think and remember is no easy task and, despite all the current research, scientists have yet to develop a reliable technique to allow them to see what’s going on in the brain. In fact, despite the fact that a mouse brain is merely a few millimetres in width, it’s not even possible to see what is happening within this tiny mass. While current brain-imaging techniques allow us to see parts of the brain, they’re not advanced enough to allow us to see anything other than the surface.
Wang has put his creative mind to work to develop another method of viewing the brain using light, which will enable scientists to monitor brain activity in real time, and which will be sharp enough to show individual brain cells. However, using light is problematic as, as soon as it enters the body, it moves around, making it very difficult to get a clear image. He therefore decided to try sound; however, ultrasound images can be blurry. Determined to find a solution, Wang then tried a combination of light and sound, which combined the speed and precision of light and the penetrative properties of sound; a technique known as photoacoustic imaging.
Wang has developed a photoacoustic microscope which is able to turn light into sound via mirrors and filters, and the sound produced into highly detailed, three dimensional images of a mouse brain. While this is fantastic news for anyone who wants to study the brain, the microscope’s use doesn’t stop there. Photoacoustic imaging has already been used to detect tumours in the breast and skin, and can even identify individual cancer cells in the blood.
So far the microscope has not been used with human brains, but Wang believes that there is no limit to what can be achieved with science.