Iodinated contrast and hyperthyroidism

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Author: Mikael Häggström [notes 1]

Risk factors

Iodinated contrast can cause thyrotoxicosis in people with hyperthyroid diseases, mainly toxic multinodular goiter, Graves’ disease, or Hashimoto’s thyroiditis.[1] Otherwise, for the general population, routine screening with thyroid function tests is generally not feasible.[1]

Management

Risk Example situations Main alternatives
Low risk
  • Treated hyperthyroidism
  • Asymptomatic / Normal T3&T4 but low TSH
  • Use contrast as otherwise indicated, and monitor (see below)
High risk
  • Untreated hyperthyroid disease
  • Symptomatic hyperthyroidism
  • Presence of cardiac disease such as atrial fibrillation[notes 2]
  • Use contrast as otherwise indicated, and give thyrostatic (see below)
  • Avoid iodinated contrast (non-contrast CT, other modality, or no exam)

Monitoring

Notify the referring physician, or the patient's family physician, or possibly put responsibility over to the patient to do this. The hyperthyroidism usually develops over 2 to 12 weeks following iodine administration.[2] Patients who develop symptoms may be treated with a β-blocker and/or methimazole.[3]

Thyrostatic

Thyrostatic medication may consist of:

  • Perchlorate (sodium or potassium perchlorate), 200 mg twice or three times daily[3]
  • Thiamazole, 20 mg/d[3]

It can be started on the day of the exam, and continued for 14 days,[3] and may thereafter be followed by monitoring.

Notes

  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Radlines:Authorship for details.
  2. Making the patient more susceptible to the effects of hyperthyroidism, if it occurs.

References

  1. 1.0 1.1 Yıldız, Sema; Kuşkonmaz, Şerife Mehlika (2016). "Effect of iodinated contrast media on thyroid: a brief review ". Journal of Health Sciences 6 (1): 12. doi:10.17532/jhsci.2016.278. ISSN 1986-8049. 
  2. "Iodinated contrast-induced thyrotoxicosis. ". CMAJ 185 (2): 144-7. 2013. doi:10.1503/cmaj.120734. PMID 23148056. PMC: 3563887. Archived from the original. . 
  3. 3.0 3.1 3.2 3.3 Lee, Sun Y.; Rhee, Connie M.; Leung, Angela M.; Braverman, Lewis E.; Brent, Gregory A.; Pearce, Elizabeth N. (2015). "A Review: Radiographic Iodinated Contrast Media-Induced Thyroid Dysfunction ". The Journal of Clinical Endocrinology & Metabolism 100 (2): 376–383. doi:10.1210/jc.2014-3292. ISSN 0021-972X.