| Medical magnetic resonance imaging device(MRI)is now one of the most advanced,expensive equipment in medical image field.Accompanied by technological progress,MRI in today's medical diagnose is more highlights advantage.To medical imaging equipment,its final imaging quality is the only basis for judging equipment performance.Therefore,how to detect MRI imaging quality becomes the primary problem of magnetic resonance imaging quality control.At present,"scan phantom-measure image" become the magnetic resonance imaging quality inspection commonly used methods.Through measuring the multiparameter image of the phantom,and contrasted with the image quality standards which are generally accepted,it could be considered as the basis of MRI system performance judgment.This paper is based on the existing problems of the existing model,mainly focuses on the description and analyses of the measurement method of the magnetic resonance phantom imaging,and design of the structure of the phantom.This paper outlined the phantom basic knowledge and characteristics,introduces several representative phantoms' structure.This article detailed the definition,method of phantom imaging multiparameter measurement,and gives diagrams to illustrate,and the new design of the phantom and the validation of effects.The main work is summarized below:1.This study comparative analyzed the scanning parameters of two kinds of commonly used phantom.After analyzed the experimental data,it was clear for magnetic resonance imaging performance test of the test requirements that the signal-to-noise ratio and image uniformity of phantom should be used to construct blank area structure design;Inspection phantom should be used with a thick layer of slope structure,and the critical value method is used to measure;Detection of phantom of the spatial resolution module should be used the line of stripe,using visual method to measure;Detection of low contrast phantom module design using a combination of multiple aperture and the depth of porous structure.2.For the ladder type testing structure layer thickness module detection of Victoreen 76-903 type phantom,this study put forward for doing signal curve between different ladder,and get quantized data by the FWHM of the curve.This improved the limitations of obtain layer thickness data through visual method,and presents a new method of quantitative detection to reduce personal error.3.This study was designed a new positioning module.The principle is that phantom malposition will lead to change the projection of module structure.The design scheme used two cube block with the same size on circular base,and placed the two cubes with a same side of edge overlapping and relative to the base plate circle symmetry.By verification of experimental test,the positioning module structure was concise and the positioning effect was intuitive.The module can help operator quickly determine the deviating from the direction of phantom place,improve work efficiency,ensure the accuracy of the subsequent testing data.4.The new design of the spatial resolution of detection module adopts two sets of the same line stripe structure with orthogonal design,The resolution of line stripe is from 1.25 mm(4 LP/cm)to 0.4 mm(12.5 LP/cm).This project added a dimension direction detection ability,improved the detection accuracy,expanded the application scope of the phantom,and will support the fast developing quality control work of magnetic resonance imaging equipment powerfully.5.Studied and designed a new layout of the linearity testing punctuation and make a reasonable use of the limited space of phantom.It has increased the ability of detecting edge geometric distortion.The spacing of each hole is reasonable and this will be convenient for quality control measuring. |
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