|
|||||
|
|
Image correction during large and rapid B0 variations in an open MRI system with permanent magnets using navigator echoes and phase compensation |
|
| Authors: | Jianqi Li Yi Wang Yu Jiang Haibin Xie Gengying Li |
| Affiliation: | aShanghai Key Laboratory of Functional Magnetic Resonance Imaging and Department of Physics, East China Normal University, Shanghai 200062, China;bDepartment of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA;cDepartment of Radiology, Weill Medical College of Cornell University, New York, NY 10022, USA |
| Abstract: | An open permanent magnet system with vertical B0 field and without self-shielding can be quite susceptible to perturbations from external magnetic sources. B0 variation in such a system located close to a subway station was measured to be greater than 0.7 μT by both MRI and a fluxgate magnetometer. This B0 variation caused image artifacts. A navigator echo approach that monitored and compensated the view-to-view variation in magnetic resonance signal phase was developed to correct for image artifacts. Human brain imaging experiments using a multislice gradient-echo sequence demonstrated that the ghosting and blurring artifacts associated with B0 variations were effectively removed using the navigator method. |
| Keywords: | MRI Permanent magnets B0 instability Artifacts Multislice gradient echo sequence Navigator echo |
| 本文献已被 ScienceDirect 等数据库收录！ | |