1. An MRI apparatus comprising: a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system controlled by a pulse module to transmit RF signals to an RF coil assembly; and a controller coupled to the plurality of gradient coils and the RF transceiver system and programmed to: obtain MR image signals at different echo times from a subject containing metabolites having known characteristics; and reconstruct images of the metabolites in a selected region of interest (ROI) using a probabilistic mathematical expression based on known information regarding an image acquisition process and using a spatial distribution of the metabolites to account for artifacts in the images.