Dynamic lymphoscintigraphy with Tc-99m human serum albumin.

Dynamic studies of the lymphatic systems of 26 cases, of which 4 were healthy volunteers, were performed using an intradermal injection of Tc-99m human serum albumin (Tc-99m HSA). With the assistance of a computer, sequential images and time-activity curves of lymphatic vessels and/or lymph nodes were obtained for a period of 30 min after the injection from the cases who took no physical exercise. The image of the axillary or inguinal lymph nodes was identified 2-4 min after injection in cases with a normal lymphatic flow. The delayed appearance of radionuclide, the collateral pathways and the obstruction of the lymphatic system were clearly observed in patients with a flow disorder. The clearance rate at the injection site of Tc-99m HSA was approximately twice as fast as that of Tc-99m rhenium sulfide colloid. The high pressure in the dense connective tissue caused by intradermal injection and the high specific radioactivity of Tc-99m HSA were thought to be important factors for obtaining excellent dynamic lymphoscintigraphy.