Getting a Radioiodine I-123 Scan and Uptake Test
If you have symptoms of hyperthyroidism, such as weight loss, nervousness, palpitations, or heat intolerance, your healthcare provider may order a I-123 scan and uptake test to evaluate your thyroid function. This molecular radiology test uses a small amount of radioactive iodine (I-123) which is a radiopharmceutical that can help measure how much iodine your thyroid gland absorbs from your blood. This can allow your medical team to diagnose the cause of your hyperthyroidism and guide the treatment options.
The radioiodine I-123 scan and uptake test is also sometimes recommended for diagnosis when hypothyroidism (low thyroid) is suspected.