Renal artery stenosis can be encountered in two clinical settings: young patient with fibromuscular dysplasia (FMD) or elderly patient with atherosclerosis. In FMD typically the mid and distal renal artery is affected and more commonly on the right. In contrast the proximal and origin of the renal artery is usually affected in atherosclerosis.

Haemodynamically significant renal artery stenosis can be defined by an elevated PSV at the site of stenosis greater than 180-200 cm/sec. The renal artery PSV to aortic PSV ratio usually exceeds 3.5. Pulsed Doppler can demonstrate aliasing at the site of stenosis with immediate downstream turbulent flow. There can be associated dampening of the arterial waveform in the intrarenal segmental arteries characterized by the parvus-tardus waveform or the internal arterial waveform can be entirely normal.