Colour duplex US with calculation of the RI and delta RI of intrarenal arteries is a valuable non-invasive test assessing the haemodynamic effects of a RAS. Low costs and safety support the use of the Doppler technique in screening for renovascular disease.

In patients with chronic liver disease CCDS is a noninvasive method to demonstrate spontaneous portosystemic shunts due to portal hypertension. The method provides information concerning patency and flow direction of the collateral veins.