^99mTc-DTPA Renal Dynamic Imaging In Evaluating The Function Of Duplex Kidneys In Adult Patients

Objective:To explore ^99mTc-DTPA renal dynamic imaging in evaluating the function of duplex kidneys in adult patients.Methods:A retrospective study was conducted on 19 patients diagnosed with duplex kidney by B-ultrasound or abdominal CT from June 2011 to June 2020 who were subjected to^99mTc-DTPA renal dynamic imaging in our department（15 females,4 males,aged 18-70years）.In addition,20 age-matched patients with normal ^99mTc-DTPA renal dynamic imaging treated in our department for urinary tract infection and other symptoms were selected as the control group（8 females,12 males）.After imaging,the upper and lower halves of both the normal and duplex kidneys were delineated,and the renography,glomerular filtration rate（GFR）and uptake rate of both parts of the kidneys were obtained.The independent two-sample T-test,Wilcoxon signed-rank test,one-way ANOVA,least significant difference（LSD）test and Kruskal-Wallis H test were used for statistical analysis.Results:There were 19 patients with 20 duplex kidneys（1 patient with bilateral duplex kidneys）,13 on the left and 7 on the right.The time-activity curves of 9 patients were normal;of the remaining 11 abnormal curves,4 were continuously ascending,3 were parabolic,and 4 were low-level prolonged.T_max,T_1/2and renal clearance could not be evaluated due to serious renal function injury in 4 patients in the experimental group.T_maxwas not observed in 3 kidneys.T_1/2was not observed in 7 kidneys.Independent two-sample T-tests were performed to compare the GFR of the duplex kidneys in the experimental group and the normal kidneys of the control group,and the difference was statistically significant（P=0.008）.One-way ANOVA was performed to compare the total GFR among the normal renography group,the abnormal renography group and the control group,followed by the LSD test to compare the mean values between pairs of groups;the difference was statistically significant（P=0.008）.The independent two-sample T-test or Wilcoxon signed-rank test was selected based on whether all data from both the affected kidney and the contralateral kidney in the experimental group obeyed a normal distribution.Results there were statistically significant differences in the renal clearance rate between the affected kidney and the contralateral kidney in the experimental group（P=0.009）,while there were no statistically significant differences in T_max（P=0.101）,t_1/2（P=0.158）and GFR（P=0.324）.Among the 20 affected kidneys in the experimental group,the upper and lower parts of the kidneys of 16 patients were clearly distinguishable,while the other 4 affected kidneys could not be accurately delineated due to serious hydronephrosis and other reasons.In the distinguishable 16 duplex kidneys,the uptake rate relative to that of the whole affected kidney was less than 30%for 3,30%～50%for 6,and>50%for 7 of the replicated kidneys.The Kruskal-Wallis H test was used to compare the three different uptake intervals,and the results showed there were no significant differences in total GFR（P=0.385）,T_max（P=0.466）and renal clearance rate（P=0.348）.This suggests that when the uptake rate of the replicated kidneys was≥50%,its value in evaluating renal function was unreliable.Conclusion:（1）Patients with normal renography with duplex kidney usually maintain good renal function;The abnormal renography is often accompanied by abnormal renal function.（2）Among the data generated by TAC,renal clearance rate is a sensitive indicator reflecting renal clearance function.According to the results of this study,the application of renal clearance rate data can be strengthened in future work and research.（3）When the uptake rate of repeated kidney≥50%occurs,the numerical reliability of uptake rate is low.In this case,changes in renal function should be determined according to TAC parameters.