According to statistics delineated in different articles, the primary sites of involvement are the abdominal aorta and iliac arteries comprising 30% of symptomatic patients; the femoral and popliteal arteries consisting of 80 to 90% of patients, and the more distal vessels, including the tibial and peroneal arteries making 40 to 50% of patients (McDermott, 2006, S2). Mechanically and topographically, atherosclerotic lesions occur preferentially at arterial branch points, which are sites of increased turbulence leading to altered shear stress, and hence injury to the tunica intima. Epidemiologic and demographic data suggest that the distal vasculature is most commonly involved in elderly individuals, mostly in patients with diabetes mellitus (Marso and Hiatt, 2006, 921-929).
The history and physical examination are usually sufficient to establish the diagnosis of peripheral arterial disease (PAD). An objective assessment of the severity of disease is obtained by noninvasive techniques. These include digital pulse volume recordings; Doppler flow velocity waveform analysis; duplex ultrasonography, which combines B-mode imaging and pulse-wave Doppler examination; segmental pressure measurements; transcutaneous oximetry; stress testing, usually using a treadmill; and tests of reactive hyperemia (Mohler, III, 2003, 2306-2314). In the presence of significant PAD, the volume displacement in the leg is decreased with each pulse, and the Doppler velocity contour becomes progressively flatter. Duplex ultrasonography is often useful in detecting stenotic lesions in native arteries and bypass grafts. There is an array of nonimaging tests that can lead to a point of suspicion to these lesions; however, with the advent of modern technologies, there are numerous imaging modalities available for a more accurate graphic and visual diagnosis of this disease in real time (Begelman and Jaff, 2006, S22). Magnetic resonance angiography and conventional contrast angiography should not be used for routine diagnostic testing but are performed prior to potential revascularization. Either test is useful in defining the anatomy to assist operative planning and is also indicated if nonsurgical interventions are being considered, such as percutaneous transluminal angioplasty (PTA) or thrombolysis. Studies have suggested that magnetic resonance angiography has diagnostic accuracy comparable to that of contrast angiography (Sommerville et al., 2005, 373-377). With the availability of so many imaging modalities, it can actually be sometimes confusing about which one to use in a given clinical situation, and there is in fact a paucity of guidelines regarding this. Taking into consideration of a volume of research in this area, therefore, it could be worthwhile to undertake a literature review in order to assimilate them into a comparative study about the pros and cons of different modalities so a framework can be developed for the appropriate diagnostic modality can