3.0T MRI系统图像质量控制检测

The detection of quality control for image quality of 3.0T MRI

目的:探讨3.0T磁共振成像(MRI)系统图像质量控制情况。方法:应用美国模体实验室制造的Magphan SMR170磁共振性能模体检测美国GE公司Discovery MR 750型3.0T MRI系统的信噪比(SNR)、图像均匀性、低对比度分辨率、空间分辨率、线性度及层厚质量控制情况,并运用公式SNR=(S_中-S_外)÷SD_中、U_∑=(1-((S_(max)-S_(min))/(S_(max)+S_(min))))×100%、线性度=|(LR-LM)/LR|×100%、层厚=半高宽×0.25分别对SNR、图像均匀性、线性度及层厚进行计算,以评估3.0T MRI系统质量控制情况。结果:3.0T MRI系统的SNR为105,图像均匀性达99.13%,低对比度分辨率5 mm/0.5mm,空间分辨率6 LP/cm,线性度达0.89%,层厚偏差0.6 mm,全部指标均能够达到检测标准。结论:采取检测3.0T MRI系统SNR、图像均匀性、分辨率、线性度及层厚偏差的方法,能够较为准确获知磁共振设备的性能情况,有助于确保其长期处于理想的运行状态。

Objective： To investigate the situation of quality control of 3.0T magnetic resonance imaging（MRI） system. Methods： A series of indicators, including signal noise ratio（SNR）, image uniformity, resolution of long-scale contrast, resolution of space, linearity and quality control of slice thickness, of 3.0T MRI system were measured by using Magphan SMR170 phantom（made by the phantom laboratory in American） on the Discovery MR 750 w system which made by GE company of American. And a series of formula, including SNR=（Sinside-Soutside）÷SDinside, U∑=（1-（（S（max）-S（min））/（S（max）＋S（min））））×100%, linearity=LR-LM LR×100%, slice thickness=half of height and width ×0.25, were used to calculate SNR, image uniformity, linearity and quality control of slice thickness, and all of these results were used to evaluate the situation of quality control of 3.0T MRI system. Results： The results revealed that SNR of 3.0T MRI was 105, the imaging uniformity achieved to 99.13%, the resolution of longscale contrast was 5mm/0.5mm, the resolution of space was 6 LP/cm, linearity achieved to 0.89% and the deviation of slice thickness was 0.6mm. All of these indicators has achieved the standards of detection. Conclusion： Through detecting the SNR, imaging uniformity, resolution, linearity and the deviation of slice thickness of 3.0T MRI system, the performance of the MRI can be accurately obtained, and these contribute to ensure the equipment operating in ideal situation.