Modelling the intermediate flow regime in flow-compensated intravoxel incoherent motion MRI

Motivation: Lack of consensus in perfusion modelling in IVIM MRI, with focus on blood flow in biological tissue. Goal(s): To model perfusion in flow-compensated IVIM MRI to allow for blood velocity and correlation time quantification. Approach: Using a velocity autocorrelation function to describe the dynamics of capillary blood flow, an expression for perfusion signal attenuation was derived for flow-compensated IVIM MRI, and evaluated in healthy brain. Results: The proposed model allows for direct quantification of velocity and correlation time of blood flow, in addition to perfusion fraction and diffusion coefficient. Impact: The study presents initial proof-of-concept directly quantifying velocity and correlation time of blood flow in healthy brain using flow-compensated Intravoxel Incoherent Motion MRI. Access to these parameters can assist in characterizing tissue microvasculature in disease.