Diagnostic accuracy of magnetic resonance voiding cystourethrography for detecting vesico-ureteral reflux in children and adolescents

Abstract

• Background: The purpose of the present study is to determine the accuracy of magnetic resonance voiding cystourethrography (MRVCUG) for diagnosis of vesicoureteral reflux (VUR) in children and adolescents with recurrent urinary tract infection (UTI).

• Methods: During the cross-sectional study from May 2009 to June 2011, 30 patients' (60 kidney-ureter units) MRVCUG findings by 1.5 T magnetic resonance imaging (MRI) were compared with voiding cystourethrography (VCUG) findings in patients with urinary tract infection. The sensitivity, specificity, positive and negative predictive values for MRVCUG were calculated.

• Results: The sensitivity, specificity, positive and negative predictive values and accuracy for MRVCUG for detecting VUR were respectively 92.68% (95% CI: 80.57-97.48%), 68.42% (95% CI: 46.01-84.64%), 86.36% (95% CI:71.95-94.33%), 81.25% (95% CI:53.69-95.02%), and 85% (95% CI: 80.40-89.60%. The level of agreement between MRVCUG and VCUG findings for diagnosis VUR was very good (P < 0.001, according to Cohen’s kappa value = 0.638). Studying correlation of low grade VUR (grade I and II) and high grade VUR (grade III-V) showed a very good agreement between MRVCUG and VCUG findings (P < 0.001, Cohen’s kappa value = 0.754).

• Conclusion: MRVCUG could accurately reveal the presence and severity of VUR, especially in cases with high-grade (grade III-V) VUR in both children and adolescents.

• Keywords: Accuracy, diagnosis, magnetic resonance, vesicoureteral reflux, voiding cystourethrography