Objective To explore the application value of dynamic renal scintigraphy glomerular filtration rate (GFR) (gGFR) in patients with and without hydronephrosis.

Methods A total of 191 patients with hydronephrosis (97 men and 94 women, aged 43.35±15.91 years) and without hydronephrosis (82 men and 51 women, aged 55.31±13.54 years) who underwent plasma GFR (rGFR) and gGFR examinations from January 2015 to January 2017 were involved in this study. They were divided into normal, mild, moderate, and severe renal damage group in accordance with the renal function stratification of the guidelines of National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Each group of gGFR and rGFR was analysed and compared, and the difference in the two methods was calculated. The bias of the two measurements among the groups was examined through one-way ANOVA. If statistical differences were observed, LSD-t test was used. Differences, correlation, and agreement between gGFR and rGFR were evaluated through a paired t-test, Pearson correlation coefficients, and Bland–Altman plots, respectively.

Results gGFR was higher than rGFR in patients with and without hydronephrosis, but a significant difference was detected in patients with hydronephrosis only (70.60±22.58) mL/(1.73 m²·min) vs. (58.67±20.49) mL/(1.73 m²·min), t=9.335, P=0.000. The correlation coefficients between gGFR and rGFR were lower in patients with hydronephrosis than in patients without hydronephrosis. In the patients with hydronephrosis, gGFR was significantly higher than rGFR in the mild, moderate, and severe renal damage groups (81.01±18.40) mL/(1.73 m²·min) vs. (71.03±7.74) mL/(1.73 m²·min), (60.98±18.28) mL/(1.73 m²·min) vs. (45.85±7.60) mL/(1.73 m²·min), and (42.88±16.14) mL/(1.73 m²·min) vs. (23.65±4.04) mL/(1.73 m²·min) with significant differences(t=4.559, 8.398, 4.480, both P<0.05). Their correlation coefficients were the highest in the moderate renal damage group(r=0.461). ΔGFR of the normal, mild, moderate, and severe renal damage groups sequentially increased (−1.61±14.05), (9.99±18.81), (15.14±16.54), and (19.23±15.48) mL/(1.73 m²·min), respectively) with significant differences (F=5.595, P=0.001). The Bland–Altman plots revealed 5.76% (11/191, >5%) scatter points outside the consistency limit (L_OA), and their consistency in patients with hydronephrosis was unsatisfactory. In patients without hydronephrosis, gGFR was significantly lower than rGFR in the mild renal damage group (66.08±8.97) mL/(1.73 m²·min) vs. (70.59±8.08) mL/(1.73 m²·min) but was higher in the moderate and severe renal damage groups (45.99±9.76) mL/(1.73 m²·min) vs. (43.83±8.29) mL/(1.73 m²·min), (26.25±8.57) mL/(1.73 m²·min) vs. (20.19±5.72) mL/(1.73 m²·min) with significant differences (t=2.095, 4.907, both P<0.05). The correlation coefficients between gGFR and rGFR were the highest in the mild renal damage group (r=0.737, P=0.000). ΔGFR of the four groups sequentially increased (−5.64±16.64), (−4.51±6.23), (2.16±7.71), and (6.06±6.87) mL/(1.73 m²·min), respectively) with significant differences (F=9.446, P=0.000). The Bland–Altman plots showed 3.01% (4/133, <5%) scatter points outside L_OA, and the consistency in patients without hydronephrosis was good.

Conclusion GFR estimated by renal scintigraphy(Gates method) should be improved for patients with hydronephrosis, and plasma-based methods might be applied to them.