1. A method for detecting motion in an imaging system, the method comprising: capturing a time series of volumetric images of a region of interest at the imaging system, each volumetric image of the time series of volumetric images being captured as a series of two-dimensional slices of the region of interest; calculating a representative value for each voxel of the series of two-dimensional slices to create a representative volumetric dataset representing the region of interest; generating, for each slice of the series of two-dimensional slices, a simulated volumetric time series including time series data for the slice and the calculated representative value at all times for the other slices of the series of two-dimensional slices; and performing a volumetric registration on each of the simulated volumetric time series to provide a set of estimated motion parameters for the slice associated with the simulated volumetric time series.