Dynamics of Respiratory Motion in Slow Flow Measurement using Simultaneous Coherent and Incoherent Motion Imaging Method

Motivation: The impact of respiration on fluid flow in brain parenchyma is poorly understood and remains an on-going research topic in MRI velocimetry. Goal(s): To analyze the sensitivity of the simultaneous coherent and incoherent motion imaging (SCIMI) method to respiratory-induced phase in the brain parenchyma and to regress this phase contribution from the underlying slow-flow-induced phase. Approach: Prospectively cardiac-gated SCIMI acquisitions were obtained during three different breathing schemes. Results: Existence of strong correlations (p<0.005) between the breathing profiles and measured phase in various brain regions indicated the presence of respiration-induced phase in the SCIMI acquisition, and regression of such phases showed promising results. Impact: This study showed the sensitivity of simultaneous coherent and incoherent motion imaging method to respiration-induced phase in the brain, and an initial attempt to regress such phase accrual from the desired brain slow flows$$$–$$$an important biomarker of glymphatic function.