Urinary tract infection (UTI) is the most common and severe bacterial infection in children. Renal scarring and associated deterioration in the differential renal function is a frequent finding. Scarring may occur even in asymptomatic patients without vesicoureteric reflux.

Fifty-three children (43 M:10 F, mean age:5.3 years; range 2-10 years) with evidence of recurrent UTI were enrolled in the study. Patients with duplex or crossed fused ectopic kidneys and with acute or chronic renal failure were excluded from the study protocol. Each patient underwent ^99mTc-DMSA and ^99mTc-EC renal scintigraphy within a period of 2 weeks.

Analysis of results was performed by comparing the diagnostic accuracy of the summed ^99mTc-EC and ^99mTc-DMSA images for the detection of renal cortical scars and correlation (linear regression analysis) between the two renal scintigraphic procedures for the estimation of differential renal function. ^99mTc-DMSA imaging demonstrated scarring in 41 kidneys whereas ^99mTc-EC scintigraphy revealed scarring in 29/41 kidneys only. The percentage function of both kidneys with ^99mTc-EC and ^99mTc-DMSA showed good correlation. The r² for left kidney was 0.95 and for right kidney was 0.94.

^99mTc-EC scintigraphy has low sensitivity (70%) for the detection of cortical scarring as compared to ^99mTc-DMSA (100%) renal imaging. On the hand, ^99mTc-DMSA static imaging gives good estimate for the DRF and the values are in good agreement with the corresponding values derived from dynamic ^99mTc-EC scanning.

Raja S, Pareek V, Singh B, Sharma S, Rao KLN, Mittal BR. Comparison of ^99mTc-Ethylene Dicysteine and ^99mTc-Dimercaptosuccinic Acid Scintigraphy for the Evaluation of Cortical Scarring and Differential Renal Function in Children with Recurrent Urinary Tract Infection. J Postgrad Med Edu Res 2012;46(4):183-186.