1. Department of Pediatric Surgery, University Hospital Álvaro Cunqueiro, Vigo, Spain
2. Galicia Sur Health Research Institute, Vigo, Spain
3. Methodology and Statistics Unit, Galicia Sur Health Research Institute, Vigo, Spain
4. Department of Radiology, University Hospital Álvaro Cunqueiro, Vigo, Spain
5. Department of Pediatrics, University Hospital Álvaro Cunqueiro, Vigo, Spain