1. Apparatus for magnetic resonance imaging, comprising means for exciting magnetic resonant (MR) active nuclei in a region of interest, an array of at least two r.f. receive coils for receiving r.f. signals from the region of interest, means for creating magnetic field gradients in a phase-encode direction for spatially encoding the excited MR active nuclei, the number of phase-encode gradients corresponding to a reduced field of view compared to the region of interest, means for unfolding a representation of the data received by the coil to the array to restore the full field of view using representations of the sensitivity profiles of the individual coils of the array, and means for comparing a plurality of unfolded representations of the data for various modifications to the sensitivity profile representations used, and for selecting an unfolded representation according to a predetermined criterion.