The technique, called photoacoustic lymphangiography (PAL), is conducted with a system that uses an ultrasonic detector array to produce high-resolution 3D images, according to presenter Dr. Hiroki Kajita, of the Keio University School of Medicine in Tokyo, and colleagues.
For the study, Kajita's group imaged 20 healthy volunteers and 30 patients with lymphedema who were injected with 0.5 mL of indocyanine green in each foot or hand; photoacoustic images were acquired with a laser at near-infrared wavelengths.
The researchers found that photoacoustic lymphangiography could distinguish between blood vessels and lymphatic vessels, and it could show the depth of each vessel from the skin surface. These results led them to conclude that this new technique could be a useful tool for staging surgery for lymphedema patients.
"The actual anatomical course of each lymphatic vessel ... visualized by PAL is useful in both planning of lymphatico-venous bypassing surgery for lymphedema and locating them during the surgery," Kajita and colleagues wrote.