With which imaging methods is possible to examine venous patency in wrist area?

Ultrasound: Doppler ultrasound is the most common diagnostic technique to evaluate the flow within vessels, and is a very quick, accurate, and painless examination that is widely available.

Ultrasound: Doppler ultrasound with a high-frequency ultrasound probe stands a good chance to image veins, even when they are superficial in an area like the wrist. The complicating factor is the proximity of all the bones of the wrist, which will degrade the image. Using a high-frequency probe will (hopefully) get around this problem, as it has a lower depth of penetration and therefore less echos.