Duplex Doppler Ultrasound
Diagnostic ultrasound, sometimes called sonography, is a procedure that uses sound waves higher than the human ear can detect to examine structures and tissues within the body. A small device called a transducer is used to send sound waves into the body, which are then reflected off of internal structures. The returning sound waves (echoes) are then sent back to the same transducer and the attached equipment electronically changes the echoes into a picture of your internal structures.
A warmed gel will be applied to the skin surface to provide better contact between the transducer and the skin. The gel is easily removed, but the patient should wear easily washable clothing. Ultrasound provides a noninvasive, safe and painless means of observing soft tissue anatomy.
Ultrasound cannot be used to examine bones because bone weakens sound waves. In addition, ultrasound cannot obtain images through bowel gas. There are no known harmful effects associated with the medical use of sonography.
Duplex or duplex Doppler ultrasound is a special form of ultrasound commonly used to evaluate blood flow. It combines standard ultrasound imaging information with Doppler flow information. Doppler measures the speed and the direction of the flow of blood. It can also be useful to estimate the diameter of a blood vessel as well as the amount and location of obstruction, if any, in the blood vessel. An audible sound may be used or the flow may be shown as a graph or color display.
Abdominal duplex Doppler ultrasound requires nothing to eat or drink after midnight due to bowel gas in that area of the body. No preparation is necessary for Doppler ultrasound of the neck, arm, and leg blood vessels.
The length of time for the examination varies with the complexity of the exam and the specific reasons for which it was requested. Generally, actual scanning times can range from 30-60 minutes. For all exams, patients should allow more time for the entire visit. In many cases, follow-up exams are necessary to evaluate the progression of obstruction.
Patients should arrive 15 minutes early to process paperwork.
After the exam, patients can safely drive home and eat and drink normally.