Scientists have long sought an effective way to detect light deep within the body, especially in organs such as the brain. Now, researchers at MIT have created a new sensor that can do just that. Using a specialized MRI sensor, they’ve been able to detect light deep within tissues such as the brain with unprecedented accuracy and sensitivity.
The key to this breakthrough lies in understanding how light behaves when it enters the tissue. As it travels into the tissue, much of it is either absorbed or scattered. This makes imaging light in deep tissues extremely difficult because there is no easy way to accurately measure what is happening to it. The MIT team overcame this obstacle by designing a sensor that converts light into a magnetic signal that can be detected by MRI scanners.
Using this new MRI-based technique, the researchers were able to image photons up to 1 cm deep inside animal brains—about 10 times deeper than other imaging techniques can reach. They believe their technique may eventually be used for noninvasive optogenetics experiments and other biomedical applications that require imaging of ultra-low light levels in highly scattering media such as biological tissues.
In addition, the researchers note that their new sensor could be used for more accurate medical diagnostics and treatments involving optical measurements, such as optical coherence tomography (OCT), which is used to diagnose eye diseases like glaucoma and macular degeneration. Furthermore, they believe their technology could also be useful for medical imaging applications such as fluorescence microscopy and positron emission tomography (PET).
These findings demonstrate just how powerful MRI sensors can be when applied correctly. By converting light into magnetic signals detectable by MRI scanners, MIT researchers have opened up exciting new possibilities for detecting light deep within tissues like the brain—possibilities that may one day revolutionize medical diagnostics and treatments involving optical measurements. With further development and refinement of their technique, we may soon see even greater advances in our ability to image photons deep inside living tissues with unprecedented accuracy and sensitivity.
