The effects of finite sampling in spin‐echo or field‐echo magnetic resonance imaging

The artifacts associated with finite sampling in magnetic resonance imaging are shown to be significant when the ratio of half the sampling time, Ts/2, to transverse relaxation time, T2, is on the order of unity or greater. For both symmetric and asymmetric sampling, these artifacts include enhanced high spatial frequency image intensity (bright edges), induced systematic noise, loss of resolution, and changes in phase. Simple filtering of the raw data does not remove the problem in tissues with position-dependent T2 values. An exact deconvolution method is described to remove these problems associated with finite position-dependent T2 values.