Clinical Significance of Uptake Difference on DMSA Scintigraphy in Pediatric Urinary Tract Infection

Abstract

Purpose Disruption of normal renal development can lead to congenital anomalies of the kidney and urinary tract, including renal hypodysplasia. We aimed to clarify whether small kidney size affects clinical manifestations in children with urinary tract infection (UTI). Methods One hundred fifty-four patients who had their first symptomatic UTI between January 2014 and June 2015 were enrolled in this study. Differences in kidney size were estimated based on percent uptake of 99mTc-dimercaptosuccinic acid (DMSA) in scintigraphy. The patients who showed more than 10% difference in kidney size on DMSA scintigraphy with none or minimal cortical defects were included in group A. (group A, n=17). Laboratory, clinical, and imaging results were compared with those of the other patients (group B, n=137). Results Group A had a relatively higher incidence of vesicoureteral reflux than group B (44% vs 20%, P <0.05). The levels of plasma neutrophil gelatinase-associated lipocalin (NGAL) and serum C-reactive protein were significantly higher in group A (193 [64-337] vs 91 [59-211] ng/mL and 4.1 [0.5-11.9] vs 2.1 [0.7-5.3] ng/ mL, respectively; all P <0.05). Linear regression analysis revealed that plasma NGAL level strongly correlated with the difference in renal uptake in DMSA scintigraphy in group A (R2=0.505). Conclusion The difference in kidney size could influence the clinical course and severity of pediatric UTI.

Keywords

• small kidney
• acute pyelonephritis
• vesico-ureteral reflux
• plasma ngal
• dmsa scintigraphy