Respiratory ordered phase encoding (ROPE): a method for reducing respiratory motion artefacts in MR imaging

A method of reducing respiratory artefact when using the spin warp technique of magnetic resonance imaging is described. A respiratory signal is used to determine the order in which the rows of the data matrix are measured. The aim is to make the respiratory signal at the time of each phase encoding gradient a slowly varying function of the time integral of the gradient and hence of the row number. Data are collected during each cycle of the imaging sequence; thus the scanning time is not increased.