[Tests and imaging of the lymphatic system]

Methods for lymphatic imaging are numerous and can be roughly classified as anatomic or functional studies. Direct or indirect lymphographies provide useful informations in case of lymphostasis. Contrast lymphangiography is the only anatomical method giving precise informations either on lymphatic ducts or lymph nodes. Nevertheless this invasive method is no more indicated in cases of limb edemas. Indirect lymphographies study the spontaneous lymphatic drainage of inert particles injected into the dermis. The blue dye test is the most simple and the oldest indirect lymphography used in the positive diagnosis of a lymphostasis. It has been replaced with the indirect radionuclide lymphography which give more reliable informations. Fluorescence microlymphoangiography is an atraumatic method which permits the visualization of skin lymphatics. Indirect lymphangiography with contrast medium give reliable informations on the status of the initial lymphatics and is the best imaging method to differentiate between lipedema and lymphedema. Indirect radionuclide lymphoscintigraphy is a safe, non invasive and physiological method for the assessment of the limb lymphatic system used for morphological studies and objective measurement of the peripheral lymphatic function necessary to assess the lymphatic variation under therapy (decongestive physiotherapy, surgery, drugs).