Patient Instructions: Venous Doppler Ultrasound
- For most Doppler exams, there is no preparation involved.
- Arrive to CVI office15 minutes before your examination to register.
- Allow approximately 30-45 minutes to completely finish your examination.
- Do not wear Compression Stockings for 12 hours prior to exam.
WHAT IS A VENOUS DOPPLER ULTRASOUND?
- A Doppler ultrasound study is a test which uses sound waves to examine the structures inside the body and to evaluate blood flow at the same time.
- With this test problems with the veins can be detected.
HOW IS THE EXAMINATION PERFORMED?
- You will be asked to lie on your back with your head elevated slightly. A gel will be spread on your arms or legs on the area to be examined.
- A hand-held instrument, called a transducer, is used in the test. It looks like a microphone, and sends and receives silent, high frequency sound waves.
- The person who does the test, the sonographer, will move the transducer down the length of the arm or leg. They will be listening, looking, and putting slight pressure on the vein. The arm or leg may need to be lightly squeezed at various times, to check for the flow of blood in the vein.
- The transducer sends sound waves that pass through the skin into the body. They are reflected back to the transducer by the internal organs. These sound waves contain information that is changed into a picture of the area being examined.
- A picture of the image is recorded and interpreted by a radiologist.
- To test the blood flow, a second method is used. When the sound waves strike moving objects (like red blood cells) the pitch of the sound is changed. This process is similar to the change in the pitch of a train whistle as the train passes.
- The change in pitch can be displayed in several ways to evaluate blood flow within the body. An audible sound may be used, or the flow may be shown as a graphic or color display.
- There is no discomfort in this test.
Veins return blood to the heart. Impeded blood flow in the venous system causes pain,edema (swelling), tenderness, and increased limb size, usually at the calf, ankle, and lower thigh. Clots in the venous system may also cause pulmonary embolism (the lodging of a blood clot in the lungs) and other serious complications.