An automated approach for clinical intravascular ultrasonic palpation

Describes a clinical prototype elasticity imaging system, which we have developed for measuring the elastic properties of vascular tissues. The system was based on a commercially available ultrasound scanner, which was equipped with a 20 MHz array catheter. Sequences of radio frequency (RF) echo frames were captured from the scanner at full frame rate, and transferred directly to PC memory using a fast data acquisition system. Palpograms were created by applying a one-dimensional tracking method in combination with global motion compensation, and multi-frame averaging to several pairs of RF echo frames that were obtained near end-diastole. The results of experiments conducted on patients demonstrate that this system is capable of producing robust palpograms under physiological conditions. Additionally, good correlation was observed between low strain values and regions of calcification as identified from the intravascular ultrasound images.