TY  - JOUR
AU  - Yarach, Uten
AU  - Luengviriya, Chaiya
AU  - Stucht, Daniel
AU  - Godenschweger, Frank
AU  - Schulze, Peter
AU  - Speck, Oliver
TI  - Correction of B 0-induced geometric distortion variations in prospective motion correction for 7T MRI.
JO  - Magnetic resonance materials in physics, biology and medicine
VL  - 29
IS  - 3
SN  - 0968-5243
CY  - Heidelberg
PB  - Springer
M1  - DZNE-2020-04929
SP  - 319-332
PY  - 2016
AB  - Prospective motion correction can effectively fix the imaging volume of interest. For large motion, this can lead to relative motion of coil sensitivities, distortions associated with imaging gradients and B 0 field variations. This work accounts for the B 0 field change due to subject movement, and proposes a method for correcting tissue magnetic susceptibility-related distortion in prospective motion correction.The B 0 field shifts at the different head orientations were characterized. A volunteer performed large motion with prospective motion correction enabled. The acquired data were divided into multiple groups according to the object positions. The correction of B 0-related distortion was applied to each group of data individually via augmented sensitivity encoding with additionally integrated gradient nonlinearity correction.The relative motion of the gradients, B 0 field and coil sensitivities in prospective motion correction results in residual spatial distortion, blurring, and coil artifacts. These errors can be mitigated by the proposed method. Moreover, iterative conjugate gradient optimization with regularization provided superior results with smaller RMSE in comparison to standard conjugate gradient.The combined correction of B 0-related distortion and gradient nonlinearity leads to a reduction of residual motion artifacts in prospective motion correction data.
KW  - Algorithms
KW  - Artifacts
KW  - Brain: diagnostic imaging
KW  - Brain: physiopathology
KW  - Computer Simulation
KW  - Humans
KW  - Image Processing, Computer-Assisted: methods
KW  - Magnetic Resonance Imaging
KW  - Male
KW  - Models, Theoretical
KW  - Motion
KW  - Phantoms, Imaging
LB  - PUB:(DE-HGF)16
C6  - pmid:26861047
C2  - pmc:PMC4933014
DO  - DOI:10.1007/s10334-015-0515-2
UR  - https://pub.dzne.de/record/138607
ER  -