Effect of iodinated contrast medium on thyroid function: a study in children undergoing cardiac computed tomography

Area of Science:

• Pediatric Endocrinology
• Radiology
• Cardiovascular Imaging

Background:

• Limited research exists on iodinated contrast media's impact on pediatric thyroid function.
• Conflicting results necessitate further investigation into contrast media effects on children's thyroid health.

Purpose of the Study:

• To assess the effects of iodinated contrast medium on thyroid function in pediatric patients with congenital heart disease.
• To evaluate thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels post-cardiac CT in neonates, infants, and young children.

Main Methods:

• Retrospective study of 33 pediatric patients (10 neonates, 23 infants/young children) with congenital heart disease.
• Serum TSH, FT3, and FT4 levels measured before cardiac CT, 48 hours after, and at discharge.
• Cardiac CT performed with intravenous iopromide (370 mg iodine/mL) at 1.14±0.17 mL/kg.

Main Results:

• A significant reduction in TSH was observed at 48 hours post-contrast in both neonates (P=0.002) and older children (P=0.0005).
• TSH levels in the older children increased from 48 hours to discharge (P=0.0001).
• No mention of FT3 or FT4 changes in results.

Conclusions:

• Intravenous iodinated contrast media can cause a transient decrease in TSH levels in children with congenital heart disease undergoing cardiac CT.
• Thyroid function, specifically TSH levels, normalized by the time of hospital discharge.