提高DSA测量精度方法的研究

目的 探讨如何提高DSA测量的精度.方法 使用7根长49.8 mm、直径5 mm钢柱,等距离并排排列在检查床面上,中间的一根钢柱作为被测物放置在X线照射野的中心,其余钢柱为校准物,被测物高出校准物0、2、4、8和12 cm,分别采集图像.用上述方法分别选择床位高度0、4和8 cm,依次采集图像.在同一序列图像中,经校准...

Research on the methods to improve the measurement accuracy of DSA

Objective To discuss how to improve the measures accuracy of DSA.Methods ① 7 steel columns,length 49.8mm,diameter 5mm were used,equidistant to arrange in the checking bed side by side,the middle steel column to be as the measured object was put in the centre of X-ray irradiating field.The other steel columns were used as calibration.The measured object was higher than the calibration by 0cm,2cm,4cm,8cm and 12cm,respectively.The bed heights were chosen 0cm,4cm and 8cm respectively and the above-mentioned method was adopted to collect the images.Through calibrating,the length of the steel column was measured and the measurement accuracy was calculated in the same sequence images.In the different sequence images,adopted the extended calibration function to measure the measured thing which was the same position and height,and calculated the measurement accuracy.The above-mentioned results were analyzed by the SPSS13.0 statistics software.② The tube was made by 300 inclination to calculate the height from the measured object to the bed.The calibration object was lifted to the calculated height.After collecting the images,the extended calibration function was used to measure the length and the accuracy can be calculated.Then the calibration object was placed in the bed to measure the length and calculate the accuracy.The difference accuracy between the former and latter was analyzed by the SPSS13.0 statistics software.Results ①The difference of the bed height and the difference of vertical height and horizontal interval between the measured object and the calibration influenced the level of the measurement accuracy.There was significant difference among the measurement accuracy.Among them the height difference influenced the accuracy to be the most prominent.The accuracy of the extended calibration was the highest and up to 99.80%.②There was significant difference accuracy between the tube 300 inclination measurement method and the calibration object in the bed measurement method,the former was higher than the latter.Conclusion ①Among the bed height and vertical height and horizontal interval three influence factors of accuracy,the influence of vertical height is the most prominent.The smaller the high difference is,the higher the accuracy is.②The measurement accuracy is obviously improved by the tube 300 inclination measurement method.