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Doctor insights on: Thyroid Scan Contraindications

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Thyroid Scan (Definition)

The patient ingests radioactive iodine or has intravenous injection of radiotracer technetium to define structure, size, and function of thyroid gland. Overactive (hyperthyroid) normal, and underactive thyroid glands are determined. Sometimes autoimmune conditions and tumors of the gland can be suspected. Correlative imaging ultrasound, mr imaging, and blood tests ...Read more


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What does a thyroid scan do?

What does a thyroid scan do?

Thyroid scan: It's a nuclear medicine scan use to evaluate how well your thyroid is working. The result will give information on the size, shape, location and the overall activity of the gland. It can also tell you if a thyroid nodule is functioning or non-functioning and help your doctor determine whether a nodule biopsy is needed. More info with the link below:
http://www. Webmd. Com/a-to-z-guides/thyroid-scan. ...Read more

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How is the thyroid scan performed?

How is the thyroid scan performed?

2 types of "scans": Thyroid ultrasounds are quick and painless. They are done with some jelly on the neck and sound waves are used to visualize the thyroid and surrounding tissues. Nuclear medicine scans are done by swallowing a small amount of radioactive iodine. After some time, the iodine finds its way to thyroid tissue and "lights up" on the scan. This is painless, safe, but does take a while. Best wishes. ...Read more

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What's the purpose of thyroid scan?

What's the purpose of thyroid scan?

A thyroid scan: Uses a radioactive tracer and a special camera to measure how much tracer the thyroid gland absorbs from the blood. A thyroid scan can show the size, shape, and location of the thyroid gland. It also finds areas that are overactive or underactive and to evaluate possible masses that may be felt or seen with ultrasound. ...Read more

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How long does a thyroid scan test take?

How long does a thyroid scan test take?

Varies: A thyroid uptake and scan may be done with different isotopes and protocols resulting in scan time variation. Typically is done with i-123; you take the capsule one day and you come back the next day at 24 hr for a neck scan that takes aprox 15-20 minutes. In certain circumstances some places do this scan at 4-6 hours after you take the capsule. ...Read more

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How expensive is it to get a thyroid scan?

How expensive is it to get a thyroid scan?

Depends: Usually this is covered by your insurance. If you get a radioiodine thyroid scan it will be more expensive than a tc99m pertechnetate scan. Are you getting a scan alone or scan plus uptake? That will affect costs. I am estimating that you are looking at costs in the range of a hundred to several hundred dollars but these costs are generally set by the administration / management and not physician. ...Read more

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What do I have to do before my thyroid scan?

What do I have to do before my thyroid scan?

If hyperthyroidism: If you are having a diagnostic dose of i-123 (usually 200 microci), you should stop taking anti-thyroid medications (methimazole and ptu) and make sure you didn't have iodine-based IV contrast (used in ct scans) in the prior 6-8 weeks. For a diagnostic study a low-iodine diet is not require, unless you are going to received i-131 treatment shortly after the test. ...Read more

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What should I have to do after my thyroid scan?

What should I have to do after my thyroid scan?

Resume daily life: If thyroid scan was performed with iodine 123 or technetium 99m pertechnetate involves a low amount of radiation. The half lives are short enough (13 and 6 hours) that most irradiation will have dissipated by 24-48 hours. Whatever i123 does not accumulate in thyroid gland are excreted via kidneys, saliva, and sweat. Tc 99m usually exits via kidneys, GI tract, and saliva. I131 involves higher dose. ...Read more

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When getting a thyroid scan, what's the procedure?

When getting a thyroid scan, what's the procedure?

Thyroid scan..: There are two types of nuclear thyroid scan. One involves IV injection of a tracer. The other involves ingestion of a radioactive iodine pill. The pill is more common....Usually you will be told not to consume foods with high iodine content for a few days before scan. 1st day you ingest the pill and you come back the next day for images of the neck on a gamma camera and calculation of uptake. ...Read more

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What is the definition or description of: thyroid scan?

What is the definition or description of: thyroid scan?

Thyroid function: The patient ingests radioactive iodine or has intravenous injection of radiotracer technetium to define structure, size, and function of thyroid gland. Overactive (hyperthyroid) normal, and underactive thyroid glands are determined. Sometimes autoimmune conditions and tumors of the gland can be suspected. Correlative imaging ultrasound, mr imaging, and blood tests are used for confirmation. ...Read more

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What information do I have to bring along to do the thyroid scan?

What information do I have to bring along to do the thyroid scan?

Blood tests: It is helpful to bring along any recent thyroid function tests, such as a TSH level. Also, any recent x-rays, such as a ct scan utilizing contrast could affect the scan. What has your diet been? This may be helpful, especially if you've been eating lots of seafood. Why are you getting the scan? Any information regarding the clinical question being asked would be helpful. ...Read more

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What is the definition or description of: thyroid scan with I 123?

What is the definition or description of: thyroid scan with I 123?

Thyroid evaluation: The isotope iodine 123 is ingested by patient. It is absorbed into blood stream and accumulates in the thyroid gland. The function of gland is determined by uptake of isotope by gland, increased (hyper), normal, or decreased (hypo). The structure of the gland is visualized showing size, location, and texture (homogeneous or nodular). Nodules can be hypo- or hyperfunctioning, benign or malignant. ...Read more

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I am having a thyroid scan done. What types of food should I avoid until after the scan?

Thyroid scan prep: Generally eat nothing 2 hours before the test. Avoid foods with iodine—shellfish, iodized salt, or kelp (seaweed, including nori on sushi). Your doc should advise you concerning meds that may interfere with the test (ones with iodine, such as cough syrups, multivitamins, or the heart medicine amiodarone; thyroid meds). ...Read more

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Just got the results of thyroid scan. The range is 5% to 30% in 24hrs. Mine's is 64% first day, 70% second day and 64.8% for the last day. Help!?

Hyperthyroidism: Your values of thyroid uptake are increased indicative of probable graves disease or hyperthyroidism especially if scan showed homogeneous enlarged thyroid. Sometimes oral medication is used to control hyperthyroidism. Sometimes medical therapy does not maintain control of disease. Some people have radioactive ablation of thyroid with i131which destroys gland, patient takes daily hormone supplements. ...Read more

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What does a thyroid scan check for?

What does a thyroid scan check for?

Different things: We use thyroid scans to help distinguish between functioning and non-functioning thyroid nodules, to assess activity of the thyroid for purposes of ablation in cases of grave's disease, to follow up patients who've had their thyroid glands removed because of cancer. ...Read more

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What's the low iodine diet for the thyroid scan?

What's the low iodine diet for the thyroid scan?

Preparation: Some diagnostic centers ask patients to undergo a 2 week low-iodine diet prior to a thyroid uptake and scan. This is because the study uses radioactive iodine (i-123 or low i-131) for the test. The iodine contained in food (seafood, table salt, etc.) may compete with the iodine used for the study, and thus results may be biased. Ideally, for the study your thyroid gland should be "hungry" for iodine. ...Read more

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How soon after a thyroid scan should you wait before an uptake scan?

How soon after a thyroid scan should you wait before an uptake scan?

One after the other: The exact scanning time after taking the capsule varies according to the isotope and protocol used. For i-123 and low i-131 the uptake and the scan is usually done at 24 hours. A thyroid probe directed to your neck measures the radioiodine uptake, this is follow by a gamma camera scan which makes an image of your thyroid gland based on the radioiodine distribution. ...Read more

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Cn thyroid scan diffrentiate between benign n malignant follicular neoplsm?

NO: Hi. Nope, you need tissue (cells). Either an FNA for cytology (which may be non-diagnostic) or a surgical biopsy. Scan adds nothing to the diagnostic evaluation ...Read more

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Would a thyroid scan rule out everything no matter what the blood test resuslts were?

Would a thyroid scan rule out everything no matter what the blood test resuslts were?

No: Thyroid scan is only part of thyroid dysfunction workup. Thyroid scan usually shows functioning or nonfunctioning nodules, thyroid gland enlargement, decreased function, or goiter. Laboratory blood testing is extremely important in determining function of thyroid gland, hypo-, hyper-, or normal. Sometimes scan and blood tests differ in findings. ...Read more

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I'm due to have a thyroid scan in 3 days. Yesterday, I took two 25 mg antihistamine pills. Will this affect the results?

I'm due to have a thyroid scan in 3 days. Yesterday, I took two 25 mg antihistamine pills. Will this affect the results?

No, it should not.: The half life of most antihistamines should be less than 24 hrs and should be out of the system by then. I would check with the radiology center to confirm their policy. I would also avoid any more antihistamines until the time of testing. ...Read more

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What type of doctor can order a thyroid scan?

Many: A thyroid scan gives info about metabolic activity in the thyroid gland. Almost any doctor involved in general medical care would be able to order this test if the patients history or physical findings supported the need. Depending on test results you may require follow up with an endocrinologist or a surgeon. ...Read more

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Is a thyroid scan and raidioactive throid treatment the same?

No: A thyroid scan is a study that exposes you to a small amount of radiation and allows the radiologist to see images of the thyroid. A radioactive thyroid treatment is when you are given very large amounts of radiation in order to "kill" the overactive thyroid or thyroid cancer. ...Read more

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Need doctor's help! What do I have to do after my thyroid scan?

Need doctor's help! What do I have to do after my thyroid scan?

Thyroid scan...: There is nothing specific to do until you receive the results. Contact your doctor and discuss the results of the test to determine if any other workup is needed. ...Read more

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How soon can you have a thyroid scan after a cat scan with contrast?

About six weeks: The timing is somewhat subjective and depeds on the metabolic activity of your thyroid. Generally waiting six weeks will give an accurate reading on a nuclear thyroid scan following a contrast ct. ...Read more

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Do I have to stop propanolol and carbimazole before radioactive thyroid scan?

Do I have to stop propanolol and carbimazole before radioactive thyroid scan?

Yes for carbimazole: You should stop carbimazole at least 3 days before radioactive iodine treatment but should continue propanolol. ...Read more

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I just got my results from my thyroid scan. What does bilateral hypoechoic nodules&cysts mean?

It means: You have multiple fluid-filled of minimally cellular nodules and cysts, which are present in approx 50% of healthy normal individuals. Discuss the full findings with your doctor. ...Read more

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Would a thyroid scan and ultrasound together identify grave's disease?

No: A radioisotope 131i scan can show where iodine is picked up (usually throughout the whole gland). An ultrasound is useless. The diagnosis is based on elevated thyroid hormones T3 (liothyronine) and t4, suppressed TSH and, if necessary a marker of autoimmunity (usually a tpo ab). ...Read more

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Single hot 1 CM nodule on thyroid scan with normal thyroid blood panels & uptake. Chances of malignancy?

Single hot 1 CM nodule on thyroid scan with normal thyroid blood panels & uptake. Chances of malignancy?

Not likely: "hot" nodules are rarely cancer and most often represent benign follicular adenomas. These are also known as "autonomous" nodules because they make thyroid hormone but don't respond to the body's normal signals telling them when to stop making the hormone. The vast majority of thyroid cancer nodules are "cold" on a thyroid scan. ...Read more

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Test results are multinodular goiter so radionuclide thyroid scan?

Test results are multinodular goiter so radionuclide thyroid scan?

Need more info: Not sure what you mean by "test results" but u cannot know that u have multinodular goiter from a blood test. A thyroid ultrasound can give u this diagnosis in which case u will need a blood test called TSH to know what to do next. No thyroid scan needed unless the TSH is low. Thyroid ultrasound vs. Biopsy might be needed depends on the size and characteristics of the nodules but need more info. ...Read more

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If I had a thyroid scan that read: left lobe of gland is mildly enlarged at 5.8cm x 1.7 x 2.2. There is a avascular 3 mm hypoechoic nodule in the lower pole of the left lobe. How would I know if it was " hot or cold"?

Ultrasound results: What you are describing are ultrasound results. A hypoechoic nodule of 3 mm of size is nearly 100% benign.

The only reason to assess if a nodule is overactive (hot) or underactive (cold) is in general hyperthyroidism. If the nodule is hot, then it can be the target of therapy. This is done through a i-131 uptake and scan. ...Read more

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Will thyroid hormones or antithyroid medications interfere with a tc99m pertechnetate thyroid scan?

Not usually: Technetium is usually trapped by thyroid gland and used to determine in young children and infants the configuration of thyroid gland, hypoplasia, absence, or increased size or hyperplasia, or abnormal location. Radioactive iodine is used in older patients for determine function of thyroid gland, increased function or hyperthyroiidism or decreased function, hypothyroidism. ...Read more

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I have stable, dominant 10 mm left thyroid nodule with possible internal microcalcifications. What does it mean? Do I need thyroid scan?

Thyroidologist: Usually, in women especially multiple thyroid nodules are all benign. However, that being said, if there's any doubt a needle biopsy is the diagnostic procedure of choice. I feel that an endocrinologist or preferably a thyroidologist is best qualified to evaluate, treat and follow you. Thyroid scans or ultrasounds alone don't usually settle the problem in my experience. ...Read more

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My thyroid tests are normal. The my symptoms all point to hyperthyroidism. What can I do to convince my endocrinologist to order a thyroid scan?

My thyroid tests are normal. The my symptoms all point to hyperthyroidism. What can I do to convince my endocrinologist to order a thyroid scan?

When to stop: It is not your job to diagnose yourself or to convince an expert to do a test that they feel is unnecessary. As much as I love the internet nine time out of ten when a patient has made their own diagnosis in the internet they are wrong. You deserve to know what the doctor who is treating you has diagnosed but they are the one with the medical license here. ...Read more

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How long do I have to wait after a nuclear medicine thyroid scan, i-123, to have a fna biopsy and/or thyroid blood tests?

How long do I have to wait after a nuclear medicine thyroid scan, i-123, to have a fna biopsy and/or thyroid blood tests?

You don't wait.: Generaly speaking you do not need to wait at all after having an I 123 thyroid scan to have a biopsy. You usually have the biopsy scheduled after the results of the thyroid scan are interpreted which usually takes a day. The radiation from the I 123 is minimal. ...Read more

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I had a radioactive thyroid scan. The results show an overproducing thyroid, with a pyramidal lobe, but my TSH came back at 4.3.What could it be?

Puzzling: As you seem to know, the TSH of 4.3 means your thyroid is very unlikely to be overactive, in which case the TSH would be ...Read more

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I had a radioactive thyroid scan. The results show an overproducing thyroid, with a pyramidal lobe, but my TSH came back at 4.3.Endocronologist next?

Likely Hashimoto's: You cant tell anything about thyroid function based on a thyroid scan. This is a common mistake made by radiologists. All you can assess is how much iodine is taken up by the thyroid gland and how it appears, not how much thyroid hormone is being produced. Your TSH is borderline elevated. The most likely cause for these findings in your age group is Hashimoto's thyroiditis. Seeing an endo is good ...Read more

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46 yo female. My calcium level in blood test is 10.2. Is that high? Had thyroid scan for nodules. Would that also show parathyroid if there's an issue?

46 yo female. My calcium level in blood test is 10.2. Is that high? Had thyroid scan for nodules. Would that also show parathyroid if there's an issue?

High Clcium: Check with your local lab normals. And ask team who ordered rd it they know H better. Scan no likely to show parathyroids. ...Read more

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Can any of these CT scan, thyroid scan, and ultrasound cause cancer?

Can any of these CT scan, thyroid scan, and ultrasound cause cancer?

Yes and no: Causality is hard to prove in medicine. Multiple ct exposure - especially in the young has been associated with increase risk of certain cancer but not all kids who had cts will have cancer. Thyroid scan and ultrasound have not been specifically implicated as contributors to the process of cancer development. ...Read more

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Thyroid scan/uptake shows mild hyperthyroidism, blood-work shows hypothyroidism. What's up with that?

Thyroid scan/uptake shows mild hyperthyroidism, blood-work shows hypothyroidism. What's up with that?

Labs are right: Thyroid scan/uptake shows how active someone's thyroid is in trapping iodine, but not whether or not their thyroid is able to convert iodide to iodine and make thyroid hormone with it. In this situation, the labs tell the true story - that the thyroid can't make enough thyroid hormone. Uptakes and scans are morehelpful in people with hyperthyroidism, and don't add much info in hypothyroidism. ...Read more

Dr. Sandra Lora Cremers
13 Doctors shared insights

Thyroid (Definition)

The thyroid is an endocrine gland that sits in the lower part of the neck. It produces thyroid hormone - which ...Read more