A subject-specific local in vivo passive shimming method, focusing on the prefrontal and temporal regions, is proposed. The aim of the investigation is to show that subject variability exists in optimal passive shimming and that the proposed method can be effectively used to overcome these differences. A shimming structure capable of adjusting the position of the passive shims to within a millimeter resolution is built. The optimal shim positions for each individual subject are computed from obtained field map using a convex optimization algorithm. Passive shim experiments at predetermined fixed shim positions vs. individually adjusted shim positions were performed and compared. The results show that intersubject variability exists in the optimal shim positions and that the location-sensitive method proposed can be useful for improving main field homogeneity in vivo.
Bibliographical noteFunding Information:
Grant sponsors: This research was supported in part by the Ministry of Knowledge Economy and Korea Industrial Technology Foundation through the Human Resource Training Project for Strategic Technology, by the Young Research Program of the Ministry of Education, Science and Technology of the Republic of Korea ( 20090066931 ) and by the Acceleration Research Program of the Ministry of Education, Science and Technology of the Republic of Korea and the Korea Science and Engineering Foundation ( 2010-001538 ).
All Science Journal Classification (ASJC) codes
- Biomedical Engineering
- Radiology Nuclear Medicine and imaging