World Library  
Flag as Inappropriate
Email this Article

Radioactive iodine uptake test

Article Id: WHEBN0023909036
Reproduction Date:

Title: Radioactive iodine uptake test  
Author: World Heritage Encyclopedia
Language: English
Subject: Medical imaging, Sestamibi parathyroid scintigraphy, ICD-9-CM Volume 3, Captopril suppression test, TRH stimulation test
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Radioactive iodine uptake test

Radioactive iodine uptake test
Diagnostics
Thyroid scan with Iodine-123 for evaluation of hyperthyroidism.
ICD-9-CM 92.01
OPS-301 code 3-701

The radioactive iodine uptake test, or RAIU test, is a type of scan used in the diagnosis of thyroid problems, particularly hyperthyroidism. It is entirely different from radioactive iodine therapy (RAI therapy), which uses much higher doses to destroy cancerous cells. The RAIU test is also used as a follow up to RAI therapy to verify that no thyroid cells survived, which could potentially still be cancerous.[1]

The patient swallows radioactive iodine in the form of capsule or fluid, and its absorption by the thyroid is studied after 4–6 hours and after 24 hours with the aid of a scintillation counter. The dose is typically 0.15–0.37 MBq (4–10 μCi) of 131I sodium iodide, or 3.7–7.4 MBq (100–200 μCi) of 123I sodium iodide.[2]

The normal uptake is between 15 and 25 percent, but this may be forced down if, in the meantime, the patient has eaten foods high in iodine, such as dairy products and seafood.[3] Low uptake suggests thyroiditis, high uptake suggests Graves' disease, and unevenness in uptake suggests the presence of a nodule.[4]

I-123 has a shorter half life than I-131 (a half day vs. 8.1 days), so use of I-123 exposes the body to less radiation, but at the expense of less time to evaluate delayed scan images.[5] Also, I-123 emits gamma radiation, while I-131 emits gamma and beta radiation.[6]

Contraindications

The test is inappropriate for patients who are pregnant or breastfeeding.[4]

Additional images

References

  1. ^ [1] ThyCa: Thyroid Cancer Survivors' Association, Inc.,Radioactive Iodine (RAI).
  2. ^ Kwee, Sandi A.; Coel, Marc N.; Fitz-Patrick, David (2007). Eary, Janet F.; Brenner, Winfried, eds. "Iodine-131 Radiotherapy for Benign Thyroid Disease". Nuclear Medicine Therapy (CRC Press): 172.  
  3. ^ M. Sara Rosenthal. The Thyroid Sourcebook. McGraw-Hill, 2008. Page 140.
  4. ^ a b WebMD article on RAIU test.
  5. ^ Ain, Kenneth; Rosenthal, M. Sara (2010-08-19). The Complete Thyroid Book, Second Edition. McGraw-Hill Professional. pp. 57–.  
  6. ^ Pilling, Gwen (1999-06-24). Salters higher chemistry. Heinemann. pp. 132–.  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.