Radio-isotopic lymphography is based on lymphatic transport and reticulo-endothelial colloidopexy. Colloid is injected subcutaneously in a dose of 125 microcuries, at the level of the first interdigital space of both feet. The gamma emission sent out by this tracer is detected by seintillation probes, amplified, collected by a system of discrimination and fed to an integrator or a scaler. A functional specification is thus obtained of the accumulation of particles in the inguinal glands, expressed as a percentage of the initial activity in the foot, and set out graphically as a function of time, while at the same time a morphological examination of the groups of glands visualised by scintigraphy can be carried out.