3D near-infrared imaging gives clearer picture of cancer
An international team of scientists have found a way to let molecular imaging peer deeper into the body to visualize cancer cells with greater accuracy by using a new 3D near-infrared imaging system, reported MIT Technology Review.

The new 3D imaging system uses ultrafast cameras to capture light that has not scattered. It has been used to create richer, higher-resolution images of the molecular workings of lung cancer in mice, and with further development, it might be used to study disease in thicker tissues and in people, according to Vasilis Ntziachristos, director of the Institute for Biological and Medical Imaging at the Helmholtz Center, in Munich, and Mark Niedre, assistant professor of electrical and computer engineering at Northeastern University, in Boston, who led the research.

Niedre and Ntziachristos's imaging technique records photons that have taken a relatively straight path through the body and thus contain better imaging information. But the photons also pass through the tissue much more quickly, which is why previous imaging techniques haven't been able to exploit them. They used a combination of a light source called a femtosecond laser and an ultrafast camera to capture these so-called early-arriving photons. Light that bounces around inside the tissue before emerging doesn't get recorded by the new imaging setup, the authors noted.

"We're preferentially choosing photons with more spatial information," said Niedre. The group said they also created better models of how these photons travel, which help sharpen the images even further.

Capturing early arriving photons makes for much better pictures of the biological activity of deeper tissue. In images of mice with lung cancer, "we resolved features that you couldn't see. Not only were the images sharper, but they also revealed molecular markers of inflammation and other problems throughout the lungs. The slower imaging setup showed only the tumors themselves,” the authors wrote.

Arjun Yodh, a professor of physics and astronomy at the University of Pennsylvania and another optical-imaging pioneer, said he is skeptical that the new approach will work in thick tissues in people, where the scattering is greater than it is in a mouse's chest cavity. Niedre himself cautioned that the work is still in its early stages, and that the instrumentation and image processing will need substantial improvement before the technique can be applied to larger animals and humans.

Until that time, he said that the technique will allow researchers to study the progression of cancer in greater detail in animal models.