A high frequency intravascular ultrasound imaging system for investigation of vessel wall properties

Intravascular ultrasound imaging systems are effective in identifying and characterizing occlusive arterial disease. In order to investigate changes in vessel wall elasticity due to atherosclerosis, a real-time, high-frequency intravascular ultrasound imaging system has been developed for the study of excised artery sections in vitro. The system consists of a miniature ultrasound probe constructed from a 42-MHz lead zirconate titanate (PZT) transducers, a high-frequency scan converter, and a computer-controlled flow system. By correlating vessel wall displacement, determined from the ultrasound data, with intraluminal pressure variations recorded with a catheter-tip pressure transducer, the elastic properties of the vessel wall can be assessed. Dynamic vessel wall motion along one radial view, assessed using one-dimensional cross-correlation, corresponds well with the simultaneously measured intraluminal pressure waveform. Preliminary studies using a two-dimensional speckle tracking algorithm show potential for determination of regional variation in vessel elasticity