Effects of static and radiofrequency magnetic field inhomogeneity in ultra-high field magnetic resonance imaging.
To characterize the severe static (B(0)) and radiofrequency (B(1)) magnetic field inhomogeneity in ultra-high field (> or =7 T) magnetic resonance imaging, gradient echo (GE) and spin echo (SE) images of in vivo and postmortem human brains were acquired. The B(0) and B(1) inhomogeneity were experimentally mapped and/or numerically simulated, and correlated with the image artifacts. Whereas B(0) inhomogeneity affects predominantly GE images near air/tissue interfaces, B(1) inhomogeneity affects SE images more severely and shows non-intuitive patterns. Mapping of the B(0) and B(1) inhomogeneity is important in characterizing image artifacts. This will help develop better B(0) and B(1) inhomogeneity correction methods.
Truong
Trong-Kha
TK
Department of Radiology, The Ohio State University, Columbus, OH 43210, USA.
Chakeres
Donald W
DW
Beversdorf
David Q
DQ
Scharre
Douglas W
DW
Schmalbrock
Petra
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping / Q000379:methods*; D002102:Cadaver; D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011846:Radio Waves; D012680:Sensitivity and Specificity