Angiography is the gold standard and definitive means to diagnose RAS, except for the risk of contrast reaction. In screening for stenosis of the main renal aeries and differentiation from fibromuscular dysplasia, the use of 3D contrast enhanced MRA provides optimum method for its detection and allows the demonstration of small accessory renal aeries and segmental branches Doppler evaluation has limited application as screening modality. The clinical signs of renal aery stenosis include Renovascular hypeension and azotaemia.