Scintigraphic imaging of lower-extremity acute venous thrombosis

The need for a radiopharmaceutical that will yield a definitive diagnosis of acute venous thrombosis in the lower extremities is evident from (1) the current difficulty in making a diagnosis on the basis of clinical signs and symptoms alone; (2) the sometimes inadequate or less sensitive diagnosis made on the basis of contrast venography or ultrasound; and (3) the need to prevent pulmonary embolism, death, and other long-term sequelae that may result from undetected acute venous thrombosis. A new radiopharmaceutical was recently approved for use in the scintigraphic imaging of acute venous thrombosis in the lower extremities of patients who have signs and symptoms of acute venous thrombosis. This radiopharmaceutical (ACUTECT) is a complex of the small synthetic peptide apcitide and the radionuclide technetium (Tc) 99m (99mTc-apcitide). Apcitide binds to glycoprotein IIb/IIIa receptors, which are expressed on the surface of activated platelets, making the radiopharmaceutical specific for acute, not chronic, thrombi. 99mTc-Apcitide allows accurate imaging of the entire lower extremities, including the calf. It has an excellent safety profile, is easy to administer by injection into an antecubital vein, and allows early imaging of acute deep-vein thrombosis (10 to 60 minutes postinjection). 99mTc-Apcitide may be used as an alternative to contrast venography and a complement to ultrasonography in the detection of acute venous thrombosis in the lower extremities.