1. A magnetic resonance (MR) imaging method, comprising: acquiring MR signals having phase and magnitude at q-space locations using a diffusion sensitizing pulse sequence performed on a tissue of interest, wherein the acquired signals each comprise a set of complex Fourier encodings representing a three-dimensional displacement distribution of the spins in a q-space location, and the signals each comprise information relating to coherent motion and incoherent motion in the q-space location; determining a contribution by coherent motion to the phase of the acquired MR signals; removing the phase contribution attributable to coherent motion from the acquired MR signals to produce a complex data set for each q-space location and an image of velocity components for each q-space location; and producing a three-dimensional velocity image from the image of the velocity components.