The lymphatic system in our bodies is a circulatory system, similar to veins and arteries that transport our blood. It works like a drainage system, removing cellular waste and fluid from the surrounding tissue and helping our body fight infections.
When the lymphatic system isn’t working properly due to a blockage, trauma, or surgery, it can be difficult for doctors to see exactly where the problem is. Lymph vessels are very tiny, and they’re filled with a clear fluid that lacks natural contrast that would make it visible on a CT scan or MRI. Current Imaging technology, called lymphoscintigraphy, relies on a radioactive compound being injected into the skin. It can take 20-45 minutes for one scan, and the resulting image is small and grainy. The smallest vessels, which make up the bulk of the lymphatic system, aren’t visible at all using this technology. Another drawback of lymphoscintigraphy is it can’t capture the flow of fluid within the lymphatic vessels.
At the Conference of Lasers and Electro-Optics (CLEO), taking place this week in San Jose, CA, a team of researchers from The University of Texas Health Science Center at Houston (UTHealth) Medical School will demonstrate a new technology that can non-invasively image the human lymphatic system. The procedure is called near-infrared fluorescence lymphatic imaging (NIRFLI). A fluorescent dye and commercially-available laser diode, along with military-grade night vision devices are used to visualize the lymphatic capillaries. By taking multiple images, a movie of the lymphatics can be created.
This new imaging technology promises dramatic improvements in patient care. It will allow even the tiniest lymph vessels to be imaged, and it can measure fluid flow throughout the lymphatic system—two types of measurements that are impossible with currently available technology.
Scientist John Rasmussen, part of the UTHealth research team said, “We feel that the ability to see the lymphatics will provide opportunities to revolutionize lymphatic care.” This should offer hope to breast cancer survivors, who are at high risk for developing lymphedema. The lack of high-resolution images was a major barrier to early diagnosis for this disease. By detecting lymphedema early, before swelling occurs, doctors will be able to offer treatment options that will lead to better outcomes for their patients.
NIRFLI was developed with funding from the U.S. National Institutes of Health and in collaboration with Eva Sevick-Muraca and other scientists and engineers at UTHealth. UTHealth has licensed the technology to NIRF Imaging, Inc. for commercialization.