Abstract：MTF can be computed from PSF and ERF ,which represents spatial resolution in CT system.In PSF method, according to the point that the spread rigion should be rounded, the point spread rigion be segmented by image processing, and using mathematical transformation method to identify the center position, and then the MTF curve will be calculated.In ERF method, the goal line should be segmented by image processing, then fitting and using mathematical transformation method to make out, the offset angle can be rotated accordingly.By transform method proposed,the data of the ERF corresponding to each other, the average processing can be made directly.Experiment has proved that the proposed transformation method is accurate, effective, simplified clinical scanning conditions, and convenience for CT evaluation.
王甜甜,余晓锷. CT系统空间分辨率测量技术的改进[J]. 计量学报, 2012, 33(2): 187-192.
WANG Tian-tian,YU Xiao-e. An Improved Methord for the Measurement of Spatial Resolution in CT System. Acta Metrologica Sinica, 2012, 33(2): 187-192.
［1］Yang K, Kwan A L, Miller D F, et al. A geometric calibration method for cone beam CT systems［J］. Medical Physics, 2006, 33(6):1695-1706.
［2］Aroua A, Trueb J P, Vader J F, et al. Exposure of the Swiss population by radiodiagnostics:2003 review［J］.Health Phys,2007,92(5):442-448.
［3］Torfeh T, Beaumont S, Guédon J P, et al. Evaluation of two software tools dedicated to an automatic analysis of the CT scanner image spatial resolution［C］//Conf Proc IEEE Eng Med Biol Soc,Lyon,France,2007.
［4］Lie J, Lysaker M, Tai X C. A binary level set model and some applications to mumford-shah image segmentation［J］.IEEE Trans Image Process,2006,15(5): 1171-1181 .
［5］Schoenemann T, Kahl F, Cremers D.Curvature regularity for region-based image segmentation and inpainting: A linear programming relaxation［C］//IEEE Int Conf on Comp Vision, Japan, 2009.
［6］黄岗,严汉民.点扩散函数测量CT机MTF的应用研究［J］.医疗设备信息, 2004,(8):10-12
［7］Du L Y, Umoh J, Nikolov H N, et al. A quality assurance phantom for the performance evaluation of volumetric micro-CT systems［J］. Phys Med Biol, 2007,52(23):7087-7108.
［8］Boone J M. Determination of the presampled MTF in computed tomography［J ］.Medical Physics,2001,28(3):356-360.
［9］李萍,余晓锷,杨克柽,等.CT的空间分辨力测量技术及测试体模研究［J］.第一军医大学学报,2005,25(5):45-546
［10］杨克柽,林意群.CT图像空间分辨力的实用检测方法［J］.放射学实践, 2006, 21(3):303-305
［11］康立丽,邓晓刚,陈阳,等.影像系统MTF算法实现及分析［J］.北京生物医学工程,2002,21(3):179－182
［12］Feng X G, Hong D M, Yu X E, et al. An analysis of QA test for MSCT ［J］.China Med Computer image,2001,7(5):352-356.
2012, Vol. 33 
