Doppler ultrasound can help detect abnormalities of the veins as well as the severity of the problem so treatment can be planned.
 

No radiation or injection of any medication or contrast medium is involved in this procedure. The ultrasound machine transmits high-frequency sound waves that travel through tissue and the blood cells in your blood vessels and then bounce back to the transducer. These reflected waves are then processed by the ultrasound machine and interpreted as two-dimensional images on the screen. The ultrasound room will be quite dark for the radiologist to better see the images on the screen. The patient’s bed may be adjusted or the patient may be asked to stand up and bear weight on the leg not being examined so the other leg is more relaxed.
 

Venography, which involves the injection of a contrast material into the veins and x-ray to capture images of how the contrast material moves through the blood vessels.