Radionuclide evaluation of the superior vena cava and upper thoracic veins in mediastinal syndrome.

Radionuclide studies of the superior vena cava are non-invasive and simple to perform. These studies give information about the patency of the superior vena cava, innominate and the subclavian veins. The site and extent of obstruction can be determined. Since this technique is non-invasive or minimally invasive, it can be repeated as often as required. The anatomic and physiologic basis of this investigation and methodology of the procedure is given. Two cases are described in detail. The only other investigation giving comparable clinical information is contrast venography which is uncomfortable and carries a definite risk of allergic reaction (JPMA 36 : 65, 1986).