This is a special radiologic imaging technique which increases the radiodensity of
blood over that of surrounding structures and, therefore, increases the resolution
of the radiographic images of blood vessels. The scanning technique allows dye to
be injected intravenously to visualize, by x rays, the aorta, coronary, renal, and
iliac vessels in order to estimate the blood flow in these vessels or the presence
or absence of obstructive lesions. It is an improved technique because it can be performed
on an outpatient basis with less risk and less discomfort to the patient than direct
arteriography. In some cases, this technique will permit the exclusion of direct arteriography.