Refill model of rabbit kidney vasculature

A refill model previously developed in flow phantoms was modified to simulate the refill of cortical and medullary rabbit kidney tissues. The highly structured kidney tissues were accounted for by considering refill both within and across the scan-plane. Refill curves were acquired with ultrasound contrast from rabbit kidneys using high MI disruption pulses followed by low MI real-time imaging. The comparison of the real medullary and cortical tissues with their corresponding models resulted in an RMS error of 11% and 18%, respectively, indicating that simple assumptions about a tissue's vascular structure are predictive of refill behaviour. Tissue classification images were generated using the refill models and an exponential simplification. These images were indistinguishable and matched what is expected of a kidney, indicating that the primary distinguishing characteristic between kidney tissue types is mean transit time. However, the vascular model is useful in predicting and explaining tissue properties that affect refill behavior. (E-mail: moskalik@umich.edu)