High field microMRI velocimetric measurement of quantitative local flow curves

Performing rheo-microMRI velocimetry at high magnetic field with strong pulsed field gradients has clear advantages in terms of (chemical) sensitivity and resolution in velocities, time and space. To benefit from these advantages some artefacts need to be minimized. Significant sources of such artefacts are chemical shift dispersion due to the high magnetic field, eddy currents caused by the pulsed magnetic field gradients, and possible mechanical instabilities in concentric cylinder (CC) rheo-cells. These in particular hamper quantitative assessment of spatially resolved velocity profiles needed to construct local flow curves (LFCs) in CC geometries with millimeter gap sizes. A major improvement was achieved by chemical shift selective suppression of signals that are spectroscopically different from the signal of interest. By also accounting for imper-fections in pulsed field gradients, LFCs were obtained that were virtually free of artefacts. The approach to obtain quantita-tive LFCs in millimeter gap C...