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The purpose of this study is to take pictures of your parathyroid glands (small glands situated in the region of the thyroid) that may be causing elevated calcium. This will help the doctor diagnose your condition and give appropriate treatment as required.
On arrival a small needle will be placed into a vein in your arm or hand. Through this a radioactive tracer will be injected, which passes into your thyroid gland. Approximately 1 hour later a second injection will be given which passes into your thyroid and parathyroid glands. After this second injection the needle will be removed and you will be asked to lie down on a couch. A gamma camera will be placed over your neck and a picture of this region will be taken for 20 minutes. This will be followed by a second picture of 30 minutes duration, when the gamma camera moves around your neck. A third picture will be taken approximately 2 hours after the second injection and for this the camera will again be placed over your neck. This final picture will last for 10 minutes.
In order to get good quality pictures the gamma camera will be close and you will have to remain still. You will be asked to remove jewellery and metal objects around your neck. Removal of clothing is not usually required.
If you are pregnant, or you think you might be pregnant, you need to inform your doctor or the Nuclear Medicine staff before attending your appointment. In general, exposure to radiation during pregnancy should be kept to a minimum and it may be necessary to postpone your scan. The present guidelines recommend that breast-feeding need not be interrupted if the mother is undergoing this test; however, it is advisable to feed the baby before the injection and to express and discard any milk secreted over the first 3 hours following the injection.
We would prefer that you do not bring more than one person with you. It is advisable not to have a pregnant woman or a small child with you. This is to avoid exposing them to unnecessary radiation. It is also preferable to avoid prolonged close contact (hugging a child / sitting a child on your knee for more than half an hour) for the rest of the day.
You may eat and drink as normal. Please tell us in advance of your test if you are taking any thyroid medication or iodine-containing medication (propylthiouracil, meprobamate, phenylbutazone, sulphonamides, corticosteroids, ACTH, perchlorate, antihistamines, iodides, Lugol's solution, vitamin preparations, iodine ointments, amiodarone and iodine contact media): these interfere with the test.
Please let us know well in advance of your test if you have had any severe reactions to iodine contrast media or to iodine-containing medication.
You may feel a slight pinprick from the injection needle. Our doctors will be available during your stay in the department to answer any queries and to provide medical cover in case of any side effect from the injection we give you (please note that side effects are extremely rare).
The amount of radioactivity you receive in this study is strictly within the recommended national level. At this level, the benefit to you from a diagnosis of your condition outweighs the risk (negligible) of any harm associated with the radiation you will receive.
You may eat as normal. The more fluid you drink the better, as the radioactivity is passed out in the urine. No extra precautions need to be taken when passing urine.
The Nuclear Medicine doctor will report on the study and the result will be sent to the doctor who requested the study. He/she will be able to discuss the results with you in relation to other tests you may have had.