Lung and leg scanning with 99mTc-labelled albumin macroaggregates.

The routine injection of (99m)Tc-macroaggregated albumin into dorsal foot veins for lung scanning allows en passant assessment to be made regarding the presence of deep venous phlebitis. The radiopharmaceutical adhered to fibrin deposits in veins of calves and thighs in 103 of 386 examinations. In the 103 patients with a presumptive diagnosis of thrombophlebitis, microembolization from labelled thrombi, producing "hot spots" in the lungs, occurred in 25 cases. It is inferred that pulmonary microembolization is a very common event in patients with phlebitis.