A fibrinogen uptake test is a test that was formerly used to detect deep vein thrombosis. Radioactive labeled fibrinogen is given which is incorporated in the thrombus. The thrombus can then be detected by scintigraphy. A fibrinogen uptake test is a test that was formerly used to detect deep vein thrombosis. Radioactive labeled fibrinogen is given which is incorporated in the thrombus. The thrombus can then be detected by scintigraphy.