Near-infrared optical imaging of lymphatic function in inflammation

Objectives The human body contains approximately 12 liters of lymph, yet little is known of lymphatic flow changes that mediate infection, inflammation, or injury. Near-infrared (NIR) optical imaging affords the unique opportunity to observe effects on lymphatic function of inflammation and other system stresses.

Methods In this study, mice were administered an inflammatory agent, and lymphatic function was visualized with NIR optical imaging utilizing indocyanine green, a NIR fluorophore.

Results Systemic lymphatic propulsive flow velocity and propulsive frequency decreased dramatically in collecting lymphatic vessels at 4-24 hours after inflammatory insult, and gradually increased to normal levels after 7 days.

Conclusions NIR imaging of lymphatic flow and pulsatile changes may enable rapid evaluation of therapies, as well as assessment of inflammatory status and infection state.

Research Support DARPA-BAA08-2