ABSTRACT
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 3.0T,Siemens Trio 3.0T 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 3.0T 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.
ABSTRACT
Objective To test the spatial resolution and average glandular dose (AGD) of full field digital mammography system to obtain high-resolution and contrast breast X-ray images with the lowest dose.Methods The M12 breast X-ray performance test phantom was placed on the breast support center position,then line-pair card was put on the M12 phantom and fixed groove,and exposure was carried out with auto exposure control,28 kV tube voltage and common anode filtration combination so as to detect the spatial resolution.Half-value layer (HVL) was measured by Fluke TNT12000 ray detection tools,2 mm-thickness plate and aluminum sheets with different thicknesses,and then AGD was calculated accordingly.Results The spatial resolutions were all higher than 7 lp/mm and proved to meet the quality standard,which had the vertical spatial resolution being 8 lp/mm,the maximum value of the lateral spatial resolution being 10 lp/mm and the minimum value being 8 lp/mm.AGD was lower than 2 mGy and then proved qualified which was limited within 0.60 and 0.61 mGy.Conclusion The test of spatial resolution and AGD of full digital mammography system can assess the performance and radiation dose,reflect the performance of equipment,ensure image quality and lower radiation dose.
ABSTRACT
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 3.0T,Siemens Trio 3.0T 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 3.0T 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.
ABSTRACT
Objective To test the spatial resolution and average glandular dose (AGD) of full field digital mammography system to obtain high-resolution and contrast breast X-ray images with the lowest dose.Methods The M12 breast X-ray performance test phantom was placed on the breast support center position,then line-pair card was put on the M12 phantom and fixed groove,and exposure was carried out with auto exposure control,28 kV tube voltage and common anode filtration combination so as to detect the spatial resolution.Half-value layer (HVL) was measured by Fluke TNT12000 ray detection tools,2 mm-thickness plate and aluminum sheets with different thicknesses,and then AGD was calculated accordingly.Results The spatial resolutions were all higher than 7 lp/mm and proved to meet the quality standard,which had the vertical spatial resolution being 8 lp/mm,the maximum value of the lateral spatial resolution being 10 lp/mm and the minimum value being 8 lp/mm.AGD was lower than 2 mGy and then proved qualified which was limited within 0.60 and 0.61 mGy.Conclusion The test of spatial resolution and AGD of full digital mammography system can assess the performance and radiation dose,reflect the performance of equipment,ensure image quality and lower radiation dose.