基于ACR标准的MRI设备图像信噪比及几何精度检测研究

Detection of SNR and geometric accuracy of MRI system based on ACR standards

目的:基于美国放射学院(American College of Radiology,ACR)标准对MRI设备的图像信噪比(signal to noise ratio,SNR)及几何精度进行测量。方法:采用ACR体模,对Siemens Skyra 3.0T、Siemens Trio 3.0T与GE Excite HD1.5T 3台MRI设备的图像SNR及几何精度进行检测。图像SNR测量在第7层或8~11层进行,几何精度的测量在第5层和矢状位定位像进行。结果:Siemens Skyra 3.0T、Siemens Trio 3.0T与GE Excite HD 1.5T MRI设备所测的图像SNR分别为589.98、438.50、277.12;几何精度分别为-1.93%(X方向)、-3.20%(Y方向)、0.68%(Z方向),-0.87%(X方向)、-2.33%(Y方向)、1.49%(Z方向),0.20%(X方向)、-1.53%(Y方向)、1.69%(Z方向)。结论:对MRI设备的关键参数SNR和几何精度进行质控检测,有利于保证优质的图像,有效保障设备良好运行。

Objective To detect the SNR and geometric accuracy of MRI based on American College of Radiology（ACR）standards. Methods The SNR and geometric accuracy of Siemens Skyra 3.0 T, Siemens Trio 3.0 T and GE Excite HD 1.5T MRI were measured with ACR phantom, and the detection results were calculated according to the standards. Results The SNR values of Siemens Skyra 3.0T, Siemens Trio 3.0 T and GE Excite HD 1.5T MRI were 589.98, 438.50 and 277.12 respectively. Siemens Skyra 3.0T MRI had the values of geometric accuracy being-1.93% at X direction,-3.20% at Y direction and 0.68% at Z direction, Siemens Trio 3.0T MRI had the value of geometric accuracy being-0.87% at X direction,-2.33% at Y direction and 1.49% at Z direction,GE Excite HD 1.5T MRI had the values of geometric accuracy being 0.20% at X direction,-1.53% at Y direction and 1.69% at Z direction. Conclusion The detection of the SNR and geometric accuracy of MRI can effectively guarantee the image quality.