COMPENSATION OF VARIATIONS IN POLARIZING MAGNETIC FIELD DURING MAGNETIC RESONANCE IMAGING

摘要

PURPOSE: Compensation of variations in polarizing magnetic field during magnetic resonance imaging is provided to compensate for changes that occur in the polarizing magnetic field of an MR system due to disturbances such as the movement of large metal objects in the vicinity of the MR system. CONSTITUTION: The operation of the system is controlled from an operator console(100) which includes a keyboard and control panel(102) and a display(104). The console(100) communicates through a link(116) with a separate computer system(107) that enables an operator to control the production and display of images on the screen(104). The computer system(107) includes a number of modules which communicate with each other through a backplane. These include an image processor module(106), a CPU module(108) and a memory module(113), as a frame buffer for storing image data arrays. The computer system(107) is linked to a disk storage(111) and a tape drive(112) for storage of image data and programs, and it communicates with a separate system control(122) through a high speed serial link(115). The system control(122) includes a set of modules connected together by a backplane. These include a CPU module(119) and a pulse generator module(121) which connects to the operator console(100) through a serial link(125).