CPT® Code 93979

The CPT® Code 93979 refers to a duplex scan of the aorta, inferior vena cava, iliac vasculature, or bypass grafts, specifically indicating a unilateral or limited study. This procedure is a type of vascular ultrasound that combines two imaging techniques: B-mode and Doppler studies. The primary purpose of this scan is to evaluate the blood vessels in the specified areas, assessing both arterial inflow and venous outflow. During the procedure, a clear gel is applied to the skin to facilitate the transmission of sound waves. A B-mode transducer is then placed on the skin, which generates real-time images of the arteries and veins by emitting ultrasonic sound waves that reflect off the blood vessels. Additionally, the Doppler component of the transducer measures the pattern and direction of blood flow, providing critical information about hemodynamics. The reflected sound waves from moving blood cells are converted into audible sounds, allowing for the assessment of blood flow characteristics. Changes in the pitch of these sounds can indicate reduced blood flow or complete obstruction in a vessel. The resulting images are enhanced with color overlays to visually represent the speed and direction of blood flow, as well as any potential obstructions. Spectral Doppler analysis further aids in evaluating the anatomy and hemodynamic function, including identifying narrowing or plaque formation within the blood vessels. After the procedure, the physician reviews the findings from the duplex scan and prepares a written interpretation, which is essential for clinical decision-making and further patient management.