Quantification in peripheral angiography

The purpose of this report is to review the wide variety of quantitative methods that either augment the angiogram or improve the evaluation of peripheral vascular disease when used in conjunction with the angiogram. The term "quantitative angiography" has many connotations in this area. On the one hand it may refer to any type of measurement of vessel diameter and luminal narrowing from angiographic images, or to an analysis of relative blood flow using videodensitometric methods. In the broader context it may mean any objective hemodynamic measurement that is obtained at the time of angiography, for example, pressure drop across a stenosis or blood flow studies using Doppler techniques. Lastly there are the indirect, noninvasive measurements that angiographers use, in conjunction with the patient history and clinical examination, to interpret the angiographic images. Doppler pressure measurements and plethysmography are two examples in wide clinical use. Magnetic resonance imaging (MRI) represents a noninvasive imaging modality that can concomitantly quantitate blood flow; however, its clinical utility in the evaluation of peripheral vascular disease is yet to be established.