Contrast-Enhanced Ultrasound Perfusion Imaging in Peripheral Arterial Disease

Quantitative contrast-enhanced ultrasound (CEU) perfusion imaging, a technique originally developed to evaluate myocardial perfusion, has also been applied to evaluate limb perfusion. CEU relies on the ultrasound detection of encapsulated microbubble contrast agents that remain entirely within the vascular compartment. Advantages of CEU for assessing limb perfusion in PAD are, that is, rapid and safe and can be performed with equipment that is already present in almost all vascular medicine laboratories. It is uniquely suited for evaluating the physiologic impact of PAD because it directly assesses nutritive microvascular flow in muscle that can originate from multiple sources, including major conduit artery inflow, collateral vessel networks, or redistribution from other limb tissues and nonnutritive pathways. Moreover, by virtue of its speed, the technique is extremely well suited to imaging during or within seconds of completing exercise stress. In this chapter, the application of contrast-enhanced ultrasound (CEU) perfusion imaging in peripheral arterial disease will be discussed including details of the imaging technique and both clinical and preclinical studies.