The Design And Implementation Of A Scanning Controller For High Field And Multi-Channel MRI Spectrometer

Magnetic resonance imaging system is an imaging device which is used in the field of medical diagnosis.MRI system is mainly composed of the magnet system,the spectrometer system,and the computer system.Spectrometer is the control center of MRI system,which determines the performance of MRI system.Scanning controller is responsible for controlling the other three parts and ensuring MRI system to complete scanning work.Therefore,how to implement and optimize scanning controller becomes a key component in manufacturing an MRI system.A scanning controller of a spectrometer,which is based on PXIe(PXI Express)system is designed in this paper.Because we chose a high-performance PXIe system controller,scanning controller in this paper can be designed to replace the computer systems that control console,spectrometer and image reconstruction,that is to say,to complete sequence generation and image reconstruction.The whole software system of the scanning controller adopts LabVIEW graphical programming language implementation,including interface,sequence,hardware control and image reconstruction.To our best knowledge,this is the first time that an MRI spectrometer can be designed and implemented in PXIe system and LabVIEW.First of all,we start with the knowledge of MRI sequence,introduces some related concepts of image quality.Secondly,we explains the sequence parameter's influence of a MRI image,analyzes the relationship between these parameters and the process of computing them into spectrometer's hardware action,describes how to use LabVIEW graphical programming language to realize a sequence.And then shows the realization of reconstruction image and hardware control.Finally introduces a series of experiments to verify the functions of scanning controller and spectrometer,uses this spectrometer to work in Alltect's 1.5T MRI system.This scanning controller abounds the function of the MRI spectrometer,simplifies the design and integration of MRI system,provides a easier way to learn the principles of MRI spectrometer and MRI system.