title: Human Lymphatic Architecture and Dynamic Transport Imaged Using Near-infrared Fluorescence.
abstract: BACKGROUND
  Although the importance of lymphatic function is well recognized, the lack of real-time imaging modalities limits our understanding of its role in many diseases. In a phase 0 exploratory study, we used dynamic, near-infrared (NIR) fluorescence imaging to assess the extremes of lymphatic architecture and transport in healthy human subjects and in subjects clinically diagnosed with unilateral lymphedema (LE), a disease that can be prevalent in cancer survivors.
  
  
  RESULTS
  Active lymphatic propulsion was imaged after intradermal injections of 25 µg of indocyanine green (total maximum dose ≤400 µg) bilaterally in the arms or legs of control and subjects. Images show well-defined lymphatic structures with propulsive dye transport in limbs of healthy subjects. In LE subjects, we observed extravascular dye accumulation, networks of fluorescent lymphatic capillaries, and/or tortuous lymphatic vessels in all symptomatic and some asymptomatic limbs. Statistical models indicate that disease status and/or limb significantly affect parameters of apparent lymph propagation velocity and contractile frequency.
  
  
  CONCLUSIONS
  These clinical research studies demonstrate the potential of NIR fluorescence imaging as a diagnostic measure of functional lymphatics and as a new tool in translational research studies to decipher the role of the lymphatic system in cancer and other diseases.
authors.affiliation: Center for Molecular Imaging, The Brown Foundation Institute of Molecular Medicine at the University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Rasmussen
authors.forename: I-Chih
authors.initials: IC
authors.lastname: Tan
authors.forename: Milton V
authors.initials: MV
authors.lastname: Marshall
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Adams
authors.forename: Sunkuk
authors.initials: S
authors.lastname: Kwon
authors.forename: Caroline E
authors.initials: CE
authors.lastname: Fife
authors.forename: Erik A
authors.initials: EA
authors.lastname: Maus
authors.forename: Latisha A
authors.initials: LA
authors.lastname: Smith
authors.forename: Kyle R
authors.initials: KR
authors.lastname: Covington
authors.forename: Eva M
authors.initials: EM
authors.lastname: Sevick-Muraca