Finding Functional Lymphatic Vessels

Imaging techniques for visualisation of the lymphatic system are less developed than those for imaging of the vascular system for two main reasons. First, the lymphatic system is more difficult to “make visible”. It is not apparent to the naked eye, even under the microscope, and its organisation as a one-way transport network makes the entire system impossible to enhance with a single injection. Thus, the imaging of the lymphatic system is traditionally performed after interstitial (e.g. intradermal, subcutaneous, intramuscular) injections of tracers, and several factors must be taken into account to enable efficient uptake by the lymphatics of that specific tissue. Second, the importance of the lymphatic system in health and disease has been historically underappreciated [1].