[Thyroid functional features after diagnostic studies with iodine-containing X-ray contrast substances]

Area of Science:

• Endocrinology
• Radiology

Context:

• Iodine-containing radiopaque contrast media are extensively utilized in diagnostic imaging.
• Diagnostic procedures administer iodine doses significantly exceeding daily requirements (200,000–350,000 times).
• Coronary angiography involves parenteral iodine administration of 25–52 g, far surpassing lifetime oral intake (3–5 g).

Purpose:

• To highlight the risk of iodine-induced conditions from radiopaque drugs.
• To emphasize the increased susceptibility in older individuals with prevalent thyroid pathology.
• To discuss the link between unrecognized autonomous thyroid nodules and iodine-induced thyrotoxicosis (IIT).

Summary:

• Parenteral administration of large iodine doses can precipitate IIT in individuals with subclinical autonomous thyroid nodules.
• IIT can exacerbate pre-existing ischemic heart disease (IHD) and lead to cardiac arrhythmias.
• Screening for thyroid dysfunction and performing thyroid ultrasound before contrast administration is proposed.

Impact:

• Informs clinicians about potential thyroid complications associated with iodinated contrast media.
• Supports the consideration of pre-procedural thyroid screening in at-risk populations.
• Contributes to the ongoing debate regarding prophylactic thyrostatic treatment for individuals susceptible to IIT.