Duplex Sonography

An ultrasound method developed for the examination of blood vessels. It is used to visualize blood flow velocities.

Color-coded duplex sonography (CDUS) is of outstanding importance in the initial examination of the abdominal aorta or in screening examinations. Experienced examiners can provide extremely accurate results with modern equipment. Even leaks in stent prostheses can be detected by contrast enhancement.

https://en.wikipedia.org/wiki/Doppler_ultrasonography _([1])