Semiautomatic off-resonance correction in spiral imaging.
Spiral scanning is a promising MRI method, but one limitation is that off-resonance effects can cause image blurring. Most current off-resonance correction methods for spiral imaging require an accurate field map, which is difficult to obtain in many applications. Automatic methods can perform off-resonance correction without acquiring a field map. However, these methods are computationally inefficient and relatively prone to estimation error. This study describes a new semiautomatic off-resonance correction method that combines an automatic method with a low resolution field map acquisition for off-resonance correction in spiral scanning. Experiments demonstrate that this method is more robust than conventional automatic off-resonance correction and can provide more accurate off-resonance correction than conventional field map based methods. The proposed method is also computationally efficient and has been implemented for online reconstruction.
Chen
Weitian
W
Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA.
Meyer
Craig H
CH
D000465:Algorithms; D016477:Artifacts; D003331:Coronary Vessels / Q000033:anatomy & histology; D006257:Head; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging; D012984:Software