Intra-arterial digital subtraction angiography (DSA) is the current standard for contrast arteriography of the lower extremity replacing film-screen arteriography. Assessment of renal function is mandatory prior to arteriography as iodinated contrast media are nephrotoxic. Hydration in patients with impaired renal function prevents contrast-induced nephropathy; with DSA, small-diameter arteries can be visualized by a smaller volume of contrast medium. Advanced computer processor power has made subtraction, pixel shifting, and re-masking simple. Increasing the diameter of the sheath increases the risk of hematoma, which is the most common complication of a sheath.