The relationship between primary vesicoureteral reflux and renal scar detected by Tc 99m DMSA scintigraphy in children with urinary tract infection

Objective: The investigation of renal scarring associated with vesicoureteral reflux and urinary tract infection (UTI) is important for the prevention of complications such as hypertension and renal failure may develop in the future. The aims of this study were to evaluate the relationship between the renal scar detected by DMSA scintigraphy and primary VUR in children with UTI and to reveal the contribution of anterior-anterior oblique images in the assessment of defect in DMSA scintigraphy.Material- Method: This retrospective study has included 179 patients who were referred to our clinic for evaluation of scar by DMSA scintigraphy that VUR on VCUG and had a urinary tract infection for 4-6 months ago.Results: Renal scar was detected in 87 (26.9%) kidneys on DMSA scintigraphy. There were global defect in 35 (40.2%) and focal paranchymal defect in 52 (59.8%) of scarred kidneys. Renal scarring was more frequent in the upper parts (51.9%) of both kidneys. 24 of 92 ureterorenal units with low-grade (grade I-II) VUR on VCUG had renal scar on DMSA scintigraphy while 57 (41.6%) of 137 ureterorenal units with high-grade (III-V) VUR on VCUG had renal scar on DMSA scintigraphy. The statistically significant difference was not found between gender and the development of renal scar due to VUR (p> 0.05). Renal scar was observed only in 3 (7.9%) of 38 ureterorenal units in children under 2 years of age while renal scar was observed in 84 (29.5%) ureterorenal units in children over 2 years of age. 34 (97%) of 35 global defects were identified in posterior-posterior oblique positions and 44 (69%) of 64 focal defects were identified in anterior-anterior oblique positions on DMSA scintigraphy. An additional defect identified in the posterior-posterior oblique image wasn?t observed in the anterior-anterior oblique image. The most important risk factors for renal scarring were detected as presence of high grade VUR and over two years of age at diagnosis by multivariate logistic regression analysis (p <0.01).Conclusion: The degree of reflux and age were the important risk factors in the development of renal scarring in children with VUR who had UTI according to the findings of DMSA scintigraphy. Furthermore, anterior-anterior oblique images not provide an additional contribution to the routine DMSA imaging findings.