Correction of chemical shift misregistration by images from two different bandwidths.
One major effect caused by the different chemical shift frequencies of water and fat is the misregistration between the two components in MR images. Methods to correct misregistration are required in clinical MRI for accurate localization and artifact reduction. One of the methods uses the images scanned at opposite readout gradients to separate water and fat signal in the k-space. Its signal-to-noise ratio (SNR) achieves maximum when misregistration is around 0.9 pixels and deteriorates rapidly as the misregistration gets larger. In this work, we proposed a method to correct the chemical shift misregistration by using two data sets acquired at two different bandwidths. It is more generalized and flexible than the former method of opposite readout gradients and covers the former one as a special case. In both simulation and experiment, the new method is proved to be capable of correcting large chemical shift misregistration and maintain a good SNR.
Department of Nuclear Engineering and Management, the University of Tokyo, Tokyo 113-0033, Japan. htzhu@nuclear.jp
Haitao
H
Zhu
Kazuyuki
K
Demachi
Cuixiang
C
Pei
Masaki
M
Sekino
Mitsuru
M
Uesaka
D000465:Algorithms; D016477:Artifacts; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio