Brain Imaging: Hi-Def for Blood Vessels
At MGH, researchers have developed a technique that uses lasers to bring stunning new clarity to imaging.
Reproduced from B. J. Vakoc, et al., Nature Medicine 15: 1219-23 (2009)
Among the orderly blood vessels in this mouse’s brain tissue, the tangled mass at upper left signals trouble: a tumor. The image from the Edwin L. Steele Laboratories directed by Rakesh K. Jain was taken using optical frequency domain imaging, a technique developed at MGH by physicists Brett Bouma and Benjamin Vakoc to overcome some of the technical limitations of other microscopic methods. OFDI can peer deeper and survey larger areas of vasculature than previous methods by sending a laser beam of multiple wavelengths into the tissue and using the properties of the reflected light as measures of depth. And unlike other microscopy techniques, OFDI does not require a contrast agent, which allows images of the same tissue to be captured over days, weeks and months without having to inject a tracer repeatedly. This prevents the image from being obscured by a buildup of tracer in the animal. OFDI can currently be used in mice to examine blood vessels during tumor growth and in response to drugs.