Potential degradation in image quality due to selective averaging of phase-encoding lines in Fourier transform MRI.

The properties of the image noise for selective averaging of phase-encoding lines have been investigated. For a given acquisition time, selective averaging results in a signal-to-noise ratio penalty compared to averaging all lines equally. In addition, selective averaging yields a non uniform distribution of noise characteristics in spatial frequency space, which can result in a change in the texture of the image noise.