Ultrasonographic thyroid volume in iodine?sufficient schoolchildren aged 6–12 years: sex differences, age trends, and association with urinary iodine background

Beckground: Ultrasonographic reference values for pediatric thyroid volume may vary across populations, even in iodine?sufficient settings. We assessed thyroid volume in healthy children and examined its relationship with age, sex, and urinary iodine concentration (UIC), comparing findings with WHO/ICCIDD reference limits.

We conducted a cross?sectional study of 50 healthy children aged 6–12 years. Thyroid ultrasound was performed with a high?frequency linear probe (7.5–15 MHz). For each lobe, three dimensions were measured and lobe volume was calculated using V=L×W×T×0.479V = L \times W \times T \times 0.479V=L×W×T×0.479; total thyroid volume (TTV) was the sum of both lobes (isthmus excluded). Morning spot UIC (µg/L) was measured by the Sandell–Kolthoff method. Data were analyzed with descriptive statistics, Shapiro–Wilk normality testing, independent?samples t?tests or Mann–Whitney U, one?way ANOVA/Kruskal–Wallis, Pearson/Spearman correlations, and simple linear regression; p < 0.05 was considered significant.

Mean TTV was 4.41 ± 1.34 mL in girls (n = 25) and 4.18 ± 0.67 mL in boys (n = 25); the sex difference was not statistically significant, t(48) = 0.79, p = 0.43; mean difference = 0.236 mL; effect size small (Cohen’s d ≈ 0.22). TTV correlated positively with age (r = 0.513, p = 0.0001). UIC ranged 99–190 µg/L, indicating overall iodine sufficiency; nevertheless, UIC showed a moderate negative correlation with TTV (r = −0.408, p = 0.0033) and with right and left lobe volumes (r ≈ −0.38 to −0.43). Age did not correlate with UIC (r = 0.014, p = 0.923). The 97th percentile (P97) of TTV in boys aligned closely with WHO/ICCIDD references across age groups, whereas girls aged 9–10 years (P97 ≈ 7.15 mL) and 11–12 years (P97 ≈ 7.7 mL) exceeded reference upper limits modestly.

Conclusions: In iodine?sufficient schoolchildren, thyroid volume increases with age. No clinically meaningful sex difference in mean TTV was detected, but upper?tail values (P97) were higher among older girls, potentially reflecting early pubertal effects. The inverse association between UIC and thyroid volume supports the role of iodine adequacy in limiting thyroid enlargement even within the “sufficient” range. Population?specific reference percentiles may improve goiter assessment; children with TTV above P97, particularly with lower UIC, warrant clinical evaluation

Dr. Blerina SARACI graduated with honors from the Faculty of Medicine in the field of general medicine, Tirana in 2010 and later graduated as a radiologist in 2015. After an experience in Durres Hospital, in 2016 Dr. Saraci has exercised her clinical and academic activity in the university hospital center Mother Teresa, being attached to the pediatric hospital, the only one in the country. Dr. Saraci is also a lecturer in Radiology at the Faculty of Medicine, Tirana and Nuclear Medicine and PET CT at the Faculty of Aldent, Tirana. Dr. Saraci is an active member of WFUMB and EFSUMB certified by them in Ultrasonography Trainings and President of AUA / WFUMB COE TIRANA cours co director.