Dependence of ultrasound decorrelation on urine scatter particle concentration

We investigated the influence of scattering particles concentration on the decorrelation of ultrasound signals for urinary flow imaging in a urethra model. A flexible urethra model made from PolyVinyl Alcohol (PVA) was perfused at flow rate of 10 ml/s with five diluted urine solutions prepared from morning urine samples of 4 healthy volunteers and seven aqueous solutions containing silica gel as scattering particles. During flow, ten ultrasound RadioFrequency (RF) data sets were acquired for each solution at a pulse repetition frequency of 5 kHz. Correlation coefficients between each two sequential RF-data sets were calculated as a function of particle concentration. The results depict that average correlation increases with an increase in particle concentration. The curves derived from the urine samples of the volunteers displayed a behavior similar to that of the silica particle aqueous solutions. Therefore, we conclude that urinary flow imaging using the decorrelation method in patients might be feasible.