In the Stanford Center for Innovation in In-vivo Imaging, researchers try every imaginable way to peer into the body without opening it up, including MRIs, PET scans and x-rays. The newest and most exciting method uses lasers, gold, nanotechnology and a phenomenon called raman scattering.
Light bouncing off any molecule includes a weak fingerprint that uniquely identifies the molecule. This "raman scattering" was always too weak to compete with x-rays or MRIs. But this lab has managed to amplify it with tiny particles made from gold.
Any cell, like cancer cells for instance, with gold nanoparticles stuck to it lights up under a laser. But how do you make tiny gold particles that latch onto cancer cells?
"Five years ago, you couldn't have produced it easily. But nanotechnology, which includes the fabrication of materials (nanomaterials), has gotten to a stage of evolution where you can make these particles reliably," says Sam Gambhir, Professor of Radiology and Bioengineering. "How do you make a little gold ball and how do you keep it always 100 nanometers in size? How do you decorate on the ball molecules that help it to find cancer? All those innovations in material science make this possible now, whereas it wasn't possible previously."
Gambhir's lab has demonstrated on animals that it works and that the gold particles are safe in humans. The next step is human colonoscopies with the laser at the end of this new endoscope.
"These raman particles literally would light the way and say, 'Look! There's cancer right here,'" he says. It will be years before you could make an appointment for a raman scan. But, there is a light at the end of the tunnel.