Effect of ultrasonic kidney depth correction on glomerular filtration rate measured by renal dynamic imaging in patients with hydronephrosis

Abstract

Objective To compare the glomerular filtration rate (GFR) measured by Gates method based on renal dynamic imaging before and after ultrasonic depth correction in patients with different degrees of hydronephrosis. Methods Renal dynamic images of 113 patients (65 males, 48 females; average age: (45.7±10.3) years) with hydronephrosis from October 2015 to October 2016 were retrospectively analyzed. The GFR was also determined with cystatinC (CysC) method within 1 week. According to the degree of hydronephrosis, patients were divided into mild, moderate, severe hydronephrosis groups. The GFR (total GFR, GFR of the impaired kidney, GFR of the normal kidney) was determined by Gates method, and was measured again after the kidney depth being corrected by ultrasound. One-way analysis of variance analysis, the least significant difference t test, and paired t test were used. Results In severe hydronephrosis group (n=55), GFRs (ml·min-1·1.73 m-2) of the impaired kidney before and after the depth correction were significant different (14.9±6.2 vs 9.6±5.8; t=4.63, P 0.05). Conclusion Ultrasonic depth correction may have greater clinical significance in GFR measurement by renal dynamic imaging for patients with severe hydronephrosis. Key words: Hydronephrosis; Radionuclide imaging; Glomerular filtration rate; Ultrasonography; Technetium Tc 99m pentetate