Venous uptake of 201T1 as thallous chloride

Thallium-201, injected as thallous chloride, has been found to adhere to or be taken up by the vein into which it is injected, permitting images to be obtained of human veins up to 4 h following injection. A digoxin-insensitive rat vein model also retained 201Tl but for shorter periods of time. 201Tl uptake is independent of the solution into which it is introduced, whether 5% dextrose or 0.9% sodium chloride. This technique permits multiple delayed views of normal veins to be obtained but is of uncertain value in the evaluation of thrombophlebitis of the calf because of rather poor resolution and high cost.