Rf Pulse Design for Parallel Excitation in Magnetic Resonance Imaging
Author | : Yinan Liu |
Publisher | : |
Total Pages | : |
Release | : 2012 |
ISBN-10 | : OCLC:813296652 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Rf Pulse Design for Parallel Excitation in Magnetic Resonance Imaging written by Yinan Liu and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Parallel excitation is an emerging technique to improve or accelerate multi-dimensional spatially selective excitations in magnetic resonance imaging (MRI) using multi-channel transmit arrays. The technique has potential in many applications, such as accelerating imaging speed, mitigating field inhomogeneity in high-field MRI, and alleviating the susceptibility artifact in functional MRI (fMRI). In these applications, controlling radiofrequency (RF) power deposition (quantified by Specific Absorption Rate, or SAR) under safe limit is a critical issue, particularly in high-field MRI. This \dissertation will start with a review of multidimensional spatially selective excitation in MRI and current parallel excitation techniques. Then it will present two new RF pulse design methods to achieve reduced local/global SAR for parallel excitation while preserving the time duration and excitation pattern quality. Simulations incorporating human-model based tissue density and dielectric property were performed. Results have show that the proposed methods can achieve significant SAR reductions without enlonging the pulse duration at high-fields.