Title :
Method for Shimming a Main Magnetic Field
Author :
Ma, Lei ; Tang, Xiaoying ; Wang, Xiangqing
Author_Institution :
Beijing Inst. of Technol., Beijing
Abstract :
The article relates to a method for shimming a main magnetic field in a magnetic resonance device. The method comprises the steps of generating at least one spatially selective radio frequency pulse (RF) for exciting nuclear spin magnetization that is sensitive to the homogeneity of the main magnetic field, and applying electric currents (DX, DY, DZ) to a shim coil arrangement of the magnetic resonance device such that the main magnetic field is adjusted in accordance to the properties of the acquired magnetic resonance signal (ES). In order to provide a shimming method, in which it is avoided that the shape or size of the selected volume is influenced by the adjustment of the magnetic field distribution generated by the shim coils, the article proposes that the electric currents (DX, DY, DZ) applied to the shim coil arrangement are at least partially switched off during the generation of the spatially selective radio frequency pulse (RF) and switched on during the acquisition of the magnetic resonance signal (ES).
Keywords :
biomedical MRI; biomedical equipment; coils; applied electric currents; clinical MRI; exciting nuclear spin magnetization; magnetic resonance device; magnetic resonance signal acquisition; main magnetic field shimming method; shim coil arrangement; spatially selective radio frequency pulse; Coils; Current; Magnetic fields; Magnetic resonance; Magnetic switching; Nuclear power generation; Pulse generation; RF signals; Radio frequency; Signal generators;
Conference_Titel :
Complex Medical Engineering, 2007. CME 2007. IEEE/ICME International Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-1077-4
Electronic_ISBN :
978-1-4244-1078-1
DOI :
10.1109/ICCME.2007.4381850
