Using a specialized MRI sensor, MIT researchers have shown that they can detect light deep within tissues such as the brain. Imaging light in deep tissues is extremely difficult because as light travels into tissue, much of it is either absorbed or scattered. The MIT team overcame that obstacle by designing a sensor that converts light into a magnetic signal that can be detected by MRI (magnetic resonance imaging). This type of sensor could be used to map light emitted by optical fibers implanted in the brain, such as the…