A method of spatially imaging a nuclear magnetic resonance (NMR)parameter whose measurement requires the acquisition of spatially localized NMR signals in a sample includes placing the sample in an MRI apparatus with a plurality of MRI detectors each having a spatial sensitivity map; and applying MRI sequences adjusted to be sensitive to the NMR parameter. At least one of the MRI sequences is adjusted so as to substantially fully sample an image k-space of the sample. The remainder of the MRI sequences is adjusted to under-sample the image k-space. The method further includes acquiring image k-space NMR signal datasets; estimating a sensitivity map of each of the MRI detectors using a strategy to suppress unfolding artefacts; and applying the estimated sensitivity maps to at least one of the image k-space NMR signal data sets to reconstruct a spatial image of NMR signals that are sensitive to the NMR parameter.