Sonographic evaluation of the thyroid size in neonates

Area of Science:

• Neonatal endocrinology
• Pediatric ultrasonography
• Thyroid imaging

Background:

• Accurate thyroid size assessment in neonates is crucial for diagnosing congenital thyroid disorders.
• Existing methods for estimating neonatal thyroid size may have limitations.

Purpose of the Study:

• To validate the Yasumoto ratio (thyroid lobe transverse diameters to trachea width) as a sonographic tool for estimating neonatal thyroid size.
• To establish reference values for the Yasumoto ratio and thyroid volume in healthy, full-term neonates.

Main Methods:

• A cross-sectional study involving 125 healthy, full-term, euthyroid neonates.
• Thyroid size was assessed using the Yasumoto ratio and calculated thyroid volume via the ellipsoid formula.

Main Results:

• The mean neonatal thyroid volume was 1.00 ml (95% CI, 0.95-1.03 ml).
• The mean Yasumoto ratio was 2.29 (95% CI, 2.21-2.31).
• Normal reference intervals were established: 0.45-1.53 ml for thyroid volume and 1.71-2.87 for the Yasumoto ratio.

Conclusions:

• The Yasumoto ratio is a validated sonographic method for estimating thyroid size in neonates.
• Established reference intervals aid in identifying thyroid abnormalities.
• A Yasumoto ratio cutoff of 1.7 may assist in diagnosing thyroid dysgenesis in neonates with congenital hypothyroidism.