Addressing Intravoxel Incoherent Motion challenges through an optimized fitting framework for quantification of perfusion

摘要

Diffusion Weighted Imaging (DWI) is a noninvasive imaging technique in Magnetic Resonance Imaging (MRI), providing significant anatomical and functional information in a wide range of clinical and research studies based on the random motion of water molecules. DWI, using appropriate models, can be quantified into clinically relevant biomarkers giving insight in the complexity of the tissue microstructure. Intravoxel Incoherent Motion (IVIM) has been extensively used as a promising model in DWI for assessing cellular density and microcirculation of blood in the tissue, and quantification of these tissue characteristics into biomarkers called true diffusion and micro perfusion. A complex mathematical framework is the basis of IVIM to extract reliable and accurate measures for true diffusion and micro perfusion from the fitting process. However not all biomarkers can be approximated with equal accuracy with micro perfusion being the most sensitive to fitting errors. The most important factors hindering the evaluation are highlighted and alternative methods to mitigate the fitting errors are proposed.