Search results
Results from the WOW.Com Content Network
Low uptake suggests thyroiditis, high uptake suggests Graves' disease, [5] and unevenness in uptake suggests the presence of a nodule. [citation needed] 123 I has a shorter half-life than 131 I (a half day vs. 8.1 days), so use of 123 I exposes the body to less radiation, at the expense of less time to evaluate delayed scan images. [6]
A cold nodule is a thyroid nodule that does not produce thyroid hormone. [1] On a radioactive iodine uptake test a cold nodule takes up less radioactive material than the surrounding thyroid tissue. [1] A cold nodule may be malignant or benign. [1] On scintigraphy cold nodules do not show but are easily shown on ultrasound. [2]
Thyroid scan. A thyroid scan using a radioactive iodine uptake test can be used in viewing the thyroid. [19] A scan using iodine-123 showing a hot nodule, accompanied by a lower than normal TSH, is strong evidence that the nodule is not cancerous, as most hot nodules are benign. [20]
Iodine-123 (123 I) is a radioactive isotope of iodine used in nuclear medicine imaging, including single-photon emission computed tomography (SPECT) or SPECT/CT exams. The isotope's half-life is 13.2232 hours; [1] the decay by electron capture to tellurium-123 emits gamma radiation with a predominant energy of 159 keV (this is the gamma primarily used for imaging).
Iodine-123 whole body scan for thyroid cancer evaluation. The study above was performed after the total thyroidectomy and TSH stimulation with thyroid hormone medication withdrawal. The study shows a small residual thyroid tissue in the neck and a mediastinum lesion, consistent with the thyroid cancer metastatic disease.
Thyroid scintigraphy, in which the thyroid is imaged with the aid of radioactive iodine (usually iodine-123, which does not harm thyroid cells, or rarely, iodine-131), [31] is performed in the nuclear medicine department of a hospital or clinic. Radioiodine collects in the thyroid gland before being excreted in the urine.
A scan is also performed, wherein images (typically a center, left and right angle) are taken of the contrasted thyroid gland with a gamma camera; a radiologist will read and prepare a report indicating the uptake % and comments after examining the images. People with hyperthyroid will typically "take up" higher than normal levels of radioiodine.
Thyroid hormone uptake (T uptake or T 3 uptake) is a measure of the unbound thyroxine binding globulins in the blood, that is, the TBG that is unsaturated with thyroid hormone. [2] Unsaturated TBG increases with decreased levels of thyroid hormones. It is not directly related to triiodothyronine, despite the name T 3 uptake. [2] Reference ranges: