Duplex ultrasound of the extremities looks at the arms or legs.
Renal duplex ultrasound examines the kidneys and their blood
vessels. You may need to wear a medical gown. You will lie down
on a table, and the ultrasound technician will spread a gel over
the area being tested. The gel helps the sound waves get into
your tissues. A wand, called a transducer, is moved over the
area being tested. This wand sends out the sound waves.A
computer measures how the sound waves reflect back, and changes
the sound waves into pictures. The Doppler creates a "swishing"
sound, which is the sound of your blood moving through the
arteries and veins. You need to stay still during the exam. You
may be asked to lie in different body positions, or to take a
deep breath and hold it. Sometimes during a duplex ultrasound of
the legs, the health care provider may calculate an ankle-
brachial (ABI) index. You will need to wear blood pressure cuffs
on your arms and legs for this test. The ABI number is obtained
by dividing the blood pre