A method to control non-uniformity RF B1 field for high field magnetic resonance imaging

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.