Figure 3. Contrast enhanced ultrasound perfusion imaging of skeletal muscle at rest and during exercise in a healthy control. (A) Color coded background-subtracted contrast enhanced ultrasound (CEU) images at various time intervals after high-power destruction in calf muscle of a normal control subject at rest and immediately after cessation of contractile exercise. Note the differences in both time to peak intensity and absolute peak video intensity between rest and stress. (B) Time-intensity data for CEU destruction-replenishment perfusion imaging at rest and immediately following exercise. BG: background.