Gates法测量的分肾肾小球滤过率受对侧肾脏兴趣区设置影响的原因与改进算法

摘要

目的:针对Gates法测量分肾肾小球滤过率(GFR)时存在的一侧肾脏GFR测量值受对侧肾脏感兴趣区勾画影响的情况,探讨改进办法.方法:回顾性对125例接受肾动态显像GFR测定的患者影像资料进行再处理与分析,提出改进的分肾GFR算法,比较改进算法与Gates算法之间的关系.结果:(1)改进算法的分肾GFR与Gates算法的分肾GFR呈高度正相关(r=0.999,P=0.000),两种算法双肾总的GFR值不变.(2)Gates算法的分肾GFR与其显像剂摄取率高度正相关(r=0.999,P=0.000),但并非一一对应关系;改进算法的分肾GFR与其显像剂摄取率完全正相关(r=l.000,P=0.000),呈一一对应的关系;两种算法双肾总的GFR值与其显像剂摄取率完全正相关(r=1.000,P=0.000).(3)随着一侧肾脏感兴趣区的逐渐减小,Gates算法另一侧肾脏的GFR值亦逐渐降低,而改进算法的另一侧肾脏GFR值则不随之改变.结论:改进的分肾GFR算法保证了肾脏总GFR值不受影响,避免Gates算法中分肾GFR值相互影响的缺点,有利于保持分肾GFR测量结果的重复性、可靠性.%Objective To analyze the reasons why the calculation of glomerular filtration rate (GFR) in unilateral kidney using Gates method is affected by different methods for defining contralateral kidney's region of interest (ROI),and to explore an improved Gates algorithm.Methods The imaging data of 125 patients receiving renal dynamic imaging and GFR measurement were retrospectively reprocessed and analyzed.An improved split renal GFR algorithm was proposed,and the correction and difference between the improved algorithm and Gates algorithm were analyzed.Results The split renal GFR measured with the improved algorithm and that measured with Gates algorithm showed a strongly positive correlation (r=0.999,P=0.000),and the total renal GFR was unvaried in the two algorithms.The split renal GFR of Gates algorithm had an obviously positive correlation with renal uptake rate (r=0.999,P=0.000),but the one-to-one relationship was not found between them.A completely positive correlation (r=1.000,P=0.000) and a one-to-one relationship were found between the split renal GFR of the improved algorithm and renal uptake rate.The total renal GFR of both algorithms also had a completely positive correlation with renal uptake rate (r=1.000,P=0.000).With the decreasing size of ROI in contralateral kidney,the GFR in unilateral kidney measured with Gates algorithm gradually decreased,but that measure with the improved algorithm did not alter.Conclusion The improved split renal GFR algorithm ensures that the total renal GFR of both kidneys will not be affected by the size of ROI and avoids the shortcoming of Gates algorithm (the interaction between split renal GFR),ensuring the repeatability and reliability of split renal GFR measurement.