García-Ascaso MT, et al. - In this cross-sectional study, researchers reported the normal Tvols of girls and boys 3–14 years old living in Madrid (Spain). Participants in the study were 217 children between the ages of 3 and 14. Urinary iodine was determined and a single, experienced pediatric radiologist performed cervical ultrasound examinations on the same day. From the age of 3 years, Tvol increased with age and body surface area (BSA) in both sexes. Investigators observed that Tvol was significantly larger in girls (aged 11–12) than that in boys of the same age. The 97th percentile Tvols for gender/BSA were similar to WHO reference values when comparing children 6 years of age and above, but by gender/age they were 30% larger. This research proposes ultrasound-determined reference Tvols for children between 3 and 14 years of age living in Madrid.