Example embodiments associated with characterizing a sample using NMR fingerprinting are described. One example NMR apparatus includes an NMR logic that repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The NMR apparatus may also include a signal logic that produces an NMR signal evolution from the NMR signals and a characterization logic that characterizes a tissue in the object as a result of comparing acquired signals to reference signals. Example embodiments facilitate analyzing voxels having multiple compartments that may experience magnetic exchange. The compartments may be, for example, an intracellular volume and an extracellular volume in a tissue that experiences magnetic exchange due to the movement of water between the volumes.
Multi-component voxel separation using magnetic resonance fingerprinting with compartment exchange