Decorrelation of intravascular ultrasound signals: a computer simulation study

A computer model based on the impulse response method to simulate the ultrasound field of a 30 MHz transducer was developed for studying the decorrelation properties of echo signals from an intravascular scanner. The decorrelation due to (1) lateral displacement, (2) axial displacement, (3) noise level, (4) velocity distribution and (5) variance in correlation estimate were investigated. The results show that the lateral decorrelation function can be approximated by a linear model, which provides a basis for flow quantitation by decorrelation processing. Decorrelation sources unrelated to the motion of blood particles such as noise can be ignored at intravascular imaging conditions. In conclusion, this study provides insight into the parameters that affect decorrelation-based flow assessment and predicts the feasibility of such an approach using IVUS techniques.