Magnetic resonance imaging is used to make nondestructive experimental measurements of fluid flow velocity and rock porosity inside a brine-filled Casper sandstone sample during brine injection. Two-dimensional images of these values are obtained in arbitrary cross sections, with pixel sizes on the order of 1 mm2. The data are then statistically analyzed to find the uariation of the average interstitial velocity as a function of porosity, as well as frequency distributions for both the velocity and porosity. The results show that as local porosity increases, the local flow velocity increases, according to the empirical relationship, V = 0.0669 phi + 0.0055. Thus, higher porosity regions of the core are better contacted by the displacement fluid. Results also imply bypassing of fluid around the perimeter of the core, indicating the need for a coreholder capable of sustaining higher overburden pressures on the order of 225 psi (1.55 MPa).