Title :
A method to control non-uniformity RF B1 field for high field magnetic resonance imaging
Author :
Hyoungsuk Yoo ; Gopinath, Anand ; Vaughan, J. Thomas
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN, USA
Abstract :
The higher static magnetic fields B0, in MRI systems result in higher signal to noise ratios. However, as the wavelength decreases linearly with the higher static magnetic field, image inhomogeneity occurs. This paper demonstrates the use of the convex optimization with an iterative method to improve B1+ uniformity in an anatomic region of interest by varying the magnitude and phase of each RF channel element independently. The simulation results for 16 channels for 9.4T systems are discussed in detail, with experimental results in a phantom.
Keywords :
biomedical MRI; iterative methods; phantoms; MRI system; convex optimization; high field magnetic resonance imaging; image inhomogeneity; iterative method; magnetic flux density 9.4 T; nonuniformity RF B1 field control; phantom; static magnetic field; Coils; Humans; Magnetic fields; Magnetic heads; Magnetic resonance imaging; Nonuniform electric fields; Radio frequency; Signal to noise ratio; Transmission line theory; USA Councils; Magnetic resonance imaging (MRI); RF B1 field; convex optimization; high field MRI; parallel excitation; transmission line head coil;
Conference_Titel :
Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International
Conference_Location :
Anaheim, CA
Print_ISBN :
978-1-4244-6056-4
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2010.5517294
