Software Development On The Low Field Magnetic Resonance Imaging System

Complicated environments such as microgravity and radiation in outer space have an influence on the physical and mental health of astronauts.As an advanced modern medical technology,MRI has the advantages of non-invasive,non-radiative,high soft tissue contrast,arbitrary angle and multi-layer imaging compared with traditional medical imaging methods,It plays an important role on the selection and Healthcare&Life-support system for astronauts.MRI relies on the hardware devices consisting of RF coils,gradient coils,spectrometers,and computers,which is controlled by the software running on the computer system.At present,most mature MRI softwares are used in conjunction with hardware devices,enterprises will not disclose the specifics of application software for commercial confidentiality considerations.Based on the "Low Field MRI instrument" of Chongqing University,this paper carries out the work related to the development of software platform that services to the MRI system.This paper developes a software platforms which support the MRI system,the development process of which follows the typical "Waterfall Model".Firstly,this paper analysis the business process of MRI system,thus clarify the functional requirements and non-functional requirements of the software system,and draw the use case diagram of the system.Based on the requirements analysis,the architecture of the software is designed,which is based on the MVC architecture and is divided into three layers: Representation Layer,Operation Layer and Data Layer.Representation Layer is responsible for the front-end display,Operation Layer handles the user's request,and Data Layer encapsulate the data of the software system and open the corresponding interface to Operation Layer.According to the idea of OOP and the principle of high cohesion and low coupling,the whole software is divided into four functional modules: information management,parameter management,scan control and data processing,each of which is independently coded to realize their respective functions,then,this paper introduces the mechanism and implementation process of sequence management function,scan control function,image reconstruction function.Low-field magnetic resonance images is deeply affected by the background noise,the SNR of which is low and edges of which are blurred.The traditional image denoising method is a smooth process,thus,there is a gap between noise removal and edge detail retention.In this paper,the research on the denoising method of low field MRI image is carried out.This paper indicate the causes of MRI images noise and the distribution characteristics of the noise of MRI images.On the basis of this,the research on the denoising of MRI images is carried out.In practice,PM?TV ?NLM and BM3 D denoising models are applied to denoise the low field T1 W image and the BrainWeb dataset T2 W image,then this paper analyze the advantages and disadvantages of each model.To obtain better denoising effect,this paper modify the regularity of TV model based on the neighborhood variance weighting,then verify the denoising performance and the robustness under different variance levels by the modified model.The result shows that the modified TV model this paper come up with can improve the denoising effect to some extent.Finally,this paper developed a GUI and integrated related functions,then verified it on the "Low Field MRI system" of Chongqing University.The main interface layout of the software fully considers the factors of ease for users,and partitions each function according to the frequency of use and the degree of association,which simplifies the operation of the software.This article also tests the various functions of the software system,The output of the software is compared with the expected results.The test results show that the overall function of the software is qualified,which can basically meet the requirements of the "Low Field MRI System" of Chongqing University.