Computer modeling of decorrelation patterns of transverse blood flow

The decorrelation properties of the phased array transducer, as well as the influence of red blood cell aggregation on the decorrelation properties of flowing blood are studied using computer modeling. Blood was modeled as randomly located omnidirectional point scatterers moving across the ultrasound beam. To study the influence of aggregation, blood was modeled as single scatterers and as aggregates of various lengths. The aggregates were organized parallel to the catheter and at random angles. The decorrelation patterns, in the near and far field, are in agreement with theoretical predictions from sound field calculations. Thus, the decorrelation properties of an IVUS array catheter (in relation to transverse blood flow) can be assessed from the properties of the ultrasound beam. The decorrelation of the echo signal is influenced by the characteristics of the scattering medium. However, a complex model of flowing blood, which consists of moving aggregates of various length and orientation, shows a similar decorrelation pattern to that of moving point scatterers