Exploring vessel artifacts in χ-separation

Motivation: χ-separation generates paramagnetic and diamagnetic susceptibility maps, potentially reflecting iron and myelin distribution. However, susceptibility measurements within and near vessels may introduce erroneously values due to flow effects. Goal(s): Our goal is to explore flow-induced displacment in mulit-echo GRE as a potential source of vessel artifacts, examining its effects across arteries and veins. Approach: A flow phantom simulation and an in-vivo experiment were conducted to assess the effects of flow-related displacement on χ-separation maps. Results: Flow-induced displacement creates artifacts in χ-separation, with arteries and veins affected differently based on flow velocity and vessel size. Impact: This study identifies sources of vessel artifacts in χ-separation, improving our understanding of χ-separation maps and also suggesting the need for caution when analyzing χ-separation.