Lymph node extraction of radiopaque nanoparticulates in the rabbit as measured in vivo with CT

Rationale and Objectives. The purpose of this study was to estimate in vivo extraction of lymphographic material in the popliteal node of the rabbit. Materials and Methods. Serial quantitative computed tomography (CT) of target tissues in four legs of two rabbits was performed after subcutaneous injection of an improved lymphographic contrast agent. Massage was used as a lymphotrophic intervention. Results. At 15 minutes, the mean change in Hounsfield units measured 815 in the popliteal node, 219 in afferent lymphatic vessels, and 127 in efferent lymphatic vessels. The nodal extraction of nanoparticulates from the lymph was approximately 55%. Nodal massage allowed the amount of nanoparticulate remaining in sinusoidal lymph to be estimated. Conclusion. Functional CT performed with timed studies, proper radiopaque materials, and physiologic interventions can depict in vivo lymphatic physiology under minimally invasive conditions.