Abstract: Objective To investigate the application value of diuretic excretion index(DEI) and glomerular filtration rate(GFR) calculated by renal dynamic imaging in the diagnosis and prognosis prediction of patients with chronic obstructive hydronephrosis. 
Methods Eighty-two patients with chronic obstructive hydronephrosis were selected as the research group, and 45 healthy people undergoing physical examination during the same period were selected as the control group. The DEI and GFR of the two groups were compared, the influencing factors of chronic obstructive hydronephrosis were analyzed, and the diagnostic value of DEI and GFR in chronic obstructive hydronephrosis was evaluated. The renal dynamic imaging parameters of patients with different degrees of hydronephrosis were compared, and the correlation between renal dynamic imaging parameters and the degree of hydronephrosis was analyzed. The application value of DEI and GFR in the 1-month prognosis prediction of patients with chronic obstructive hydronephrosis was analyzed. 
Results The renal dynamic imaging parameters DEI and GFR in the research group were lower than those in the control group(P＜0.05). Both DEI and GFR were influencing factors of chronic obstructive hydronephrosis(P＜0.05). The area under the ROC curve(AUC) of DEI and GFR for the diagnosis of chronic obstructive hydronephrosis was 0.784 and 0.827, respectively, and the AUC of combined detection was the largest(0.910). DEI and GFR were lower in patients with severe chronic obstructive hydronephrosis than in patients with moderate and mild disease, and lower in patients with moderate disease than in patients with mild disease(P＜0.05). DEI and GFR were negatively correlated with the degree of hydronephrosis in patients with chronic obstructive hydronephrosis(r=-7.360, -8.015, P＜0.05). Patients with high DEI and GFR had a lower rate of no renal function at 1 month after surgery, as compared with those with low DEI and GFR(P＜0.05). There was a negative correlation between DEI, GFR and the rate of no renal function in patients with chronic obstructive hydronephrosis(r=-0.614, -0.653, P＜0.05).  
Conclusion Calculation of DEI and GFR by renal dynamic imaging has certain application value in the diagnosis and prognosis prediction of chronic obstructive hydronephrosis.

Key words: hydronephrosis, diuretic excretion index, glomerular filtration rate