Title :
A method to control non-uniformity RF B1 field for high field magnetic resonance imaging
Author :
Yoo, Hyoungsuk ; Gopinath, Anand ; Vaughan, T.
Author_Institution :
Univ. of Minnesota, Minneapolis, MN, USA
Abstract :
The higher static magnetic fields $B_0$, 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 $B_1Λ +$ 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 9.4 T systems are discussed in detail, with experimental results in a phantom.
Keywords :
biomedical MRI; phantoms; MRI system; convex optimization; high field magnetic resonance imaging; image inhomogeneity; nonuniformity RF B1 field control; phantom; static magnetic fields; Biomedical imaging; Control systems; Magnetic fields; Magnetic resonance imaging; Medical control systems; Microwave imaging; Monitoring; Optimization methods; Radio frequency; Signal to noise ratio;
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.2010.5516743
