Lymphoscintigraphy (LS) in infants and children: techniques and scintigraphic patterns

Full text: Radionuclide imaging of the lymphatic system with intradermal injection of radiopharmaceutical is a rapid, safe and simple technique for the evaluation of lymphatic abnormalities in infants and children. 99Tcm-antimony sulphide colloid is the agent of choice. The radiopharmaceutical (dose 5 mBq in 0.1 ml) is injected intradermally into both limbs being investigated. Emla cream is useful to reduce the initial discomfort of the injection. Imaging is performed immediately for approximately 30-60 min to assess the flow rate and lymph channels to the draining node fields. Further imaging at 2 and 4 h may be necessary. Normal LS in the lower limbs shows the tracer to pass into lymphatics almost immediately and channels are usually visualized within 5 min. In the lower limbs, symmetrical lymph flow to nodes are seen in the groin, iliac and paravertebral region with activity later seen in the liver. In 31 patients studied over the last 3 years, 17 studies were normal and 14 were abnormal: Klippel-Trenaunay-Weber syndrome (n = 4) with delayed flow and dermal backflow; congenital lymph/vascular malformations (n = 6) with various delayed flow patterns and focal accumulations; congenital lymphoedema (n 3) and pulmonary lymphangiectasia (n = 1). Aplasia and hypoplasia of lymph systems are readily identified. In conclusion, LS is a valuable diagnostic technique to assess lymph flow and diagnose lymphatic malformations and the causes of lymphoedema in children