The application of nuclear magnetic resonance flow imaging to the study of Poiseuille flows of solid/liquid suspensions is described. The basic imaging method is presented along with results on suspensions with solid particle loading levels up to 52 vol. % and viscosities up to 7kPoise. The most concentrated suspensions are non-Newtonian, and the NMR flow data show evidence for deviations from a simple parabolic velocity profile in straight pipes. Cross-sectional intensity images derived from the flow image data on concentrated suspensions are non-uniform. Possible explanations for these results are discussed in terms of current rheological understanding of suspension flow and relaxation weighting phenomena in the NMR imaging experiments.