Diffusion weighted magnetic resonance imaging of kidneys in children with vesicoureteral reflux

Abstract

Purpose The apparent diffusion coefficient (ADC) which obtain from diffusion-weighted magnetic resonance imaging (DWI), is a quantitative parameter representing the renal function and parenchymal damage in some renal disorders. The primary aim of this study was to investigate whether renal tissue alterations associated with vesicoureteral reflux (VUR) can be displayed by DWI. The secondary aim was to assess how ADC values change with age in kidneys with and without VUR. Materials and methods This prospective study included 46 patients (8 boys, 38 girls; mean age 7.3 ± 4.2; range 1-15 years) with VUR and 54 control subjects (21 boys, 33 girls; mean age 7.7 ± 5.2; range 1-17 years). All subjects underwent DWI of the kidneys using b value of 600 s/mm2 in addition to MR urography. The ADC values of 71 kidneys with VUR were compared with those of 81 kidneys without VUR. Results The mean ADC values were (1.93 ± 0.36) × 10-3 mm2/s, (1.97 ± 0.24) × 10-3 mm2/s, (1.83 ± 0.37) × 10-3 mm2/s, (1.98 ± 0.20) × 10 -3 mm2/s and (2.08 ± 0.42) × 10-3 mm2/s in normal kidneys, and in those with grade 1, grade 2, grade 3 and grade 4 VUR, respectively. There was no significant difference in ADC values between kidneys with and without VUR. There was a significant positive correlation between the age and ADC values both in kidneys with and without VUR (r = 0.79, p < 0.001 and r = 0.82; p < 0.001, respectively). Conclusion DWI does not reveal probable parenchymal alterations in reflux nephropathy. ADC values increase with age during childhood not only in normal kidneys but also in kidneys with VUR. © 2013 Elsevier Ireland Ltd.