Detection of Vesicoureteral Reflux Using Electrical Impedance Tomography

Objective: The purpose of this study is to detect vesicoureteral reflux (VUR) noninvasively using an electrical impedance tomography (EIT). VUR is characterized by the backflow of urine from the bladder to the kidneys. Methods: Using porcine models, small quantities of a solution mimicking the electrical properties of urine were infused into each ureter. EIT measurements were taken before, during and after the infusion using electrodes positioned around the abdomen. The collected data from 116 experiments were then processed and time-difference images reconstructed. Objective VUR detection was determined through statistical analysis of the mean change in the voltage signals and EIT image pixel intensities. Results: Unilateral VUR was successfully detected in 94.83% of all mean voltage signals and in over 98.28% of the reconstructed images. The images showed strong visual contrast between the region of interest and the background. Conclusion: In animal models, EIT has the capability to detect reflux in the kidneys with high accuracy. The results show promise for EIT to be used for screening of VUR in children. Significance: VUR is the most common congenital urinary tract abnormality in children. The condition predisposes children to urinary tract infections and kidney damage. The current gold standard diagnostic test, a voiding cystourethrogram, is invasive and uses ionizing radiation; therefore, there is a need for new tools for identifying VUR in children. This study presents a noninvasive method to detect VUR in animal models, illustrating the potential for EIT as a screening tool in clinical scenarios.