1. Pictorial depiction of the phase-masking process.
Pictorial depiction of the phase-masking process. A, Phase profile in a filtered-phase image. B, Corresponding profile of the mask created from A. Once the mask is raised to the fourth power, the vein that has a phase of −π / 2 and a mask value of 0.5 will become 1-/16 and, therefore, this vein will be almost as well suppressed as the vein with a phase of −π and f(x) = 0. GM indicates gray matter; WM, white matter.
E.M. Haacke et al. AJNR Am J Neuroradiol 2009;30:19-30
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