肾功能对Gates法肾小球滤过率实测值的影响

目的探讨肾功能对Gates法测定肾小球滤过率(GFR)实测值的影响。方法对155例慢性肾脏病(CKD)患者进行99 Tcm-DTPA肾动态显像,采用Gates法测定GFR,其中73例由两位不同操作者进行肾脏ROI的勾画,82例由同一操作者在不同的时间进行两次ROI勾画,将所得的GFR进行分析比较,观察在不同的肾功能状态下由于肾脏ROI勾画差异所得到的GFR偏离情况。结果两组病例分别由不同操作者及同一操作者进行两次ROI勾画测得的GFR比较,差异均无统计学意义(P>0.05)。CKDⅠ～Ⅳ期两次ROI勾画测得的GFR的变异系数(CV)逐渐增大。不同操作者及同一操作者的Gates法测定GFR的CV与肾功能成负相关,回归方程分别为:不同操作者,Y=―0.09 X+10.22(r=0.60);同一操作者,Y=―0.11 X+11.23(r=0.66)。结论肾功能本身是影响Gates法测量GFR准确性的因素之一,在肾功能的不同分期Gates法测定GFR存在不同程度的偏差,肾功能越差,偏差越大。

Influence of renal function on the measurement of glomerular filtration rate with Gates method

Objective To investigate the influence of renal function on the measurement of glomerular filtration rate(GFR) with Gates method.Methods In 155 cases with different kidney disease(95 male,60 female;19-83 years old),having impairment of renal function to varying degrees,renal dynamic imaging was performed by 99Tcm-DTPA and GFR was measured twice using Gates method both by two different manipulators in 73 cases and by the same manipulator at more than 3 months interval in 82 cases.Two groups of cases were divided into 4 stages according to mean GFR.All GFR at different stages in two groups were analyzed with the matched t-test to reveal if there were significant differences between the before-and-after GFR measured by different manipulators or by same manipulator at different time.Coefficient of variation(CV) of GFR at different stages was obtained to explore the relationship between CV and renal function(mean GFR).Results There were not statistically significant differences of GFR between the before-and-after GFR measured by different manipulators or by same manipulator at different time in all cases(P>0.05).With decline of renal function from stage Ⅰ to stage Ⅳ of chronic kidney disease(CKD),CV became larger.They were in negative correlation and the regression equations were Y=-0.09X+10.22(r=0.60)by two different manipulators and Y=-0.11X+11.23(r=0.66)by the same manipulator.Conclusion Deviation at different extent in measuring GFR with Gates method exists at different stages of renal function.The worse the renal function is,the greater the deviation rises.