Modern practice typically utilizes indirect angiography by computed tomography or magnetic resonance imaging as the first-line diagnostic tool for renal artery stenosis, with no established screening tool able to meaningfully impact the pre-test probability of a positive finding. Neither can any current imaging technique reliably predict patient, blood pressure, or renal outcome following renal artery revascularization, although promising developments have been made in recent years.A major mechanism of hypertension in renovascular hypertension is overproduction of renin in response to hypoperfusion. While renin levels can be useful in investigating patients likely to have secondary hypertension, in the setting of renal impairment renin levels are not particularly useful in distinguishing treatable renal artery stenosis from other causes of renal disease.