Is there a correlation between kidney size in ultrasonography and split renal function in 99mtc-dmsa renal scintigraphy

Abstract

Objective: The purpose of this study was to determine the correlation between kidney sizes in ultrasonography (USG) and split renal function in 99mTechnetium Dimercapto Succinic Acid (99mTc-DMSA) renal scintigraphy (RS) in adults, and find out cut off values of many kidney sizes to detect decreased renal function. Material and Methods: A total of 133 patients who had ultrasonography of kidney and decreased split renal function in 99mTc--DMSA were enrolled in this retrospective study. Patients were divided into two groups: Group 1 (G1) had no previous urologic operations, or no information about the kidney size, previously. Group 2 (G2) had a urologic operation at related kidney. The correlation between longitudinal size, transvers size, axial size, and split renal function of related kidney in 99mTc--DMSA was applied. Kidney size cut-off values were calculated to detect <30%, <20%, and <10% split renal functions, respectively. Results: There was a linear correlation between longitudinal kidney size in USG and split renal function in 99mTc--DMSA in G1 (p=0.001), but there wasn’t in G2 (p=0.125). The longitudinal kidney size cut-off value to detect <30%, <20%, and <10% split renal functions in 99mTc--DMSA were calculated as 71 mm (with 80% sensitivity), 66 mm (with 90% sensitivity), and 56 mm (with 90% sensitivity) for G1, and 95mm(with 80% sensitivity), 82mm(with 90% sensitivity), and 52mm(with 90% sensitivity) for G2, respectively. Conclusions: There is a correlation between kidney size and split renal function in 99mTc-DMSA-RS, and detected cut-off values will help to decide about split renal function without need for 99mTc-DMSA-RS.