Spiral sampling in magnetic resonance imaging-the effect of inhomogeneities.

A study of a spiral scan echo planar method in the presence of static field inhomogeneities is presented. The approach consists of obtaining the samples over the Fourier plane trajectory of the spiral scan, as modified by the inhomogeneities. The resulting images are compared to a Cartesian scan echo-planar method also subjected to inhomogeneities in the static field. The conclusion is that the spiral scan is more sensitive to this type of inhomogeneity. The possibility of compensating for the inhomogeneities during the reconstruction procedure is suggested by a preliminary experimental result.