Contrast Enhanced Ultrasound Perfusion Imaging in Skeletal Muscle.

The ability to accurately evaluate skeletal muscle microvascular blood flow has broad clinical applications for understanding the regulation of skeletal muscle perfusion in health and disease states. Contrast-enhanced ultrasound (CEU) perfusion imaging, a technique originally developed to evaluate myocardial perfusion, is one of many techniques that have been applied to evaluate skeletal muscle perfusion. Among the advantages of CEU perfusion imaging of skeletal muscle is that it is rapid, safe and performed with equipment already present in most vascular medicine laboratories. The aim of this review is to discuss the use of CEU perfusion imaging in skeletal muscle. This article provides details of the protocols for CEU imaging in skeletal muscle, including two predominant methods for bolus and continuous infusion destruction-replenishment techniques. The importance of stress perfusion imaging will be highlighted, including a discussion of the methods used to produce hyperemic skeletal muscle blood flow. A broad overview of the disease states that have been studied in humans using CEU perfusion imaging of skeletal muscle will be presented including: (1) peripheral arterial disease; (2) sickle cell disease; (3) diabetes; and (4) heart failure. Finally, future applications of CEU imaging in skeletal muscle including therapeutic CEU imaging will be discussed along with technological developments needed to advance the field.