II. Indications

  1. Hyperthyroidism diagnosis and management

III. Mechanism

  1. Iodine-123 (I-123) uptake by the Thyroid Gland is measured
  2. Typical uptake is 15-25% in 24 hours

IV. Causes: Diffusely Low radioidoine uptake with hyperthyrodism

  1. Medications and other intakes
    1. Exogenous Thyroid intake
    2. Excessive exogenous Iodine
    3. Amiodarone
  2. Transient Thyroiditis
    1. Subacute Thyroiditis
    2. Postpartum Thyroiditis (5-8% Incidence)
    3. Painless lymphocytic Thyroiditis

V. Causes: Focal low RAIU (cold Nodule) with Hypothyroidism

  1. Requires biopsy for Thyroid Cancer evaluation

VI. Causes: High Radioiodine Uptake with Hyperthyroidism

  1. Diffusely increased uptake
    1. Thyrotoxicosis (e.g. Grave's Disease)
  2. Localized increased uptake (Hot Nodule)
    1. Hyperfuntioning Thyroid Nodule

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Ontology: Radioactive iodine uptake (C0203778)

Definition (NCI) A type of nuclear test of the thyroid that measures how much radioactive iodine is taken up by the thyroid gland in a given time period. This test is performed to evaluate thyroid function, particularly when blood tests of thyroid function (for example, T3 or T4 levels) have abnormal results. (from Medline Plus Medical Encyclopedia)
Concepts Diagnostic Procedure (T060)
SnomedCT 3223000, 169124009, 146341006, 241375005
English I 131 Uptake, Radioactive Iodine Uptake, RAIU - Radioact iodine uptake, iodine radioactive uptake, iodine radioactive uptake (procedure), radioactive iodine uptake, uptake radioactive iodine, Radioiodine uptake study (procedure), Radioiodine uptake study, Radioactive iodine uptake, RAIU - Radioactive iodine uptake, Radioactive iodine uptake (procedure), I-131 Uptake Test, I-131 Uptake and Scan, Radio-iodine uptake study
Spanish estudio de captación de radioyodo, estudio de captación de radioyodo (procedimiento), captación de yodo radiactivo (procedimiento), captación de yodo radiactivo

Ontology: Radioiodine thyroid imaging study (C0412434)

Concepts Diagnostic Procedure (T060)
SnomedCT 241378007
English Radioiodine thyroid imaging, Radioiodine thyroid imaging study, Radioiodine thyroid imaging study (procedure)
Spanish estudio de imágenes tiroideas con radioyodo (procedimiento), estudio de imágenes tiroideas con radioyodo, estudio de imágenes tiroideas con yodo radiactivo