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The purpose of this study is to see how well the thyroid takes up iodine.
On arrival, an anaesthetic cream will be applied to a vein in your child's arm or the back of the hand. Approximately 30-60 minutes later a radioactive tracer will be given into that vein through a venflon (small needle). For this your child will be lying down on a couch, with a gamma camera placed over the neck. The gamma camera will take a picture of the thyroid for 1 hour. When we are 30 minutes into the study, we will inject a substance called sodium perchlorate through the venflon. In order to get good quality pictures the gamma camera will be close and your child will have to remain still. Removal of clothing is not required, but jewellery and metal objects around the neck region must be removed.
We would prefer that not more than two individuals accompany your child. It is advisable not to have a pregnant woman or small child with you. This is to avoid exposing them to unnecessary radiation.
Your child may eat and drink as normal. Please tell us if he/she is on any thyroid medication and iodine containing supplements (propylthiouracil, meprobamate, phenylbutazone, sulphonamides, corticosteroids, ACTH, perchlorate, antihistamines, enterovioform, iodides, Lugol's solution, vitamin preparations, iodine ointment, amiodarone, and iodine contrast media): these interfere with the thyroid test.
Your child may feel a slight pinprick from the injection needle. Our doctors will be available during your child's stay in the department to answer any queries and to provide medical cover in case of any side effect from the injection we give (please note that side effects are extremely rare).
The amount of radioactivity given in this study is strictly within the recommended national level. We reduce the dose given to your child according to his/her weight. The benefit to your child from a diagnosis of his/her condition outweighs the risk (negligible) of any harm associated with the radiation he/she will receive.
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 your child may have had.