Age-dependent reference values of the thyroid gland in pediatric population; from routine computed tomography data

Purpose: To evaluate age-dependent reference values for measurements of the thyroid gland in pediatric patients. Method: In total 425 chest and neck computed tomography images of pediatric patients without pathology of the thyroid gland were retrospectively reviewed. Measurements of the thyroid gland were obtained in three dimensions (width, depth, length). The total volume was the sum of volumes of each lobe. Measurements were compared among the six groups according to age from 0 to 18 years. Results: There were moderate to strong positive linear correlations between age and all values (r = 0.58-0.82, all p < 0.001). The total volume of the thyroid gland showed a strong positive linear correlation with the three linear measurements of each lobe (all r > 0.7, all p < 0.001). Among these measurements, the depth of the right lobe showed the highest Pearson correlation coefficient with the total volume of the thyroid gland (r = 0.859). Conclusion: The depth of right lobe could be a representative measurement of total thyroid gland volume, similar to prior findings in adults.