A magnetic resonance imaging system (200, 300) acquires magnetic resonance data (242, 244). A processor (230) controls the magnetic resonance imaging system to execute instructions (250, 252, 254, 256, 258) which cause the processor to repeatedly: control (100) the magnetic resonance imaging system to acquire magnetic resonance data including magnetic resonance navigator data (244); create (102) a set of navigator vectors by extracting the navigator data from each portion of the magnetic resonance data; construct (104) a dissimilarity matrix (246, 400, 700, 800, 900, 1000, 1100, 1400, 1500) by calculating a metric between each of the set of navigator vectors; generate (106) a matrix classification (248) of the dissimilarity matrix using a classification algorithm; and control (108) the magnetic resonance imaging system to modify acquisition of the magnetic resonance data using the matrix classification.