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Thyroid scan (I 123)

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Can I have a thyroid scan if I am pregnant or breastfeeding?

If there is a possibility that you are pregnant or if you are currently breastfeeding please inform the department before your appointment as we will likely have to re-schedule.

    Can I bring someone with me?

    Whenever possible, you should attend your appointment alone, unless you need a carer to support any additional needs.

      How long will my appointment take?

      The first part of your appointment will take 30 minutes. You can then leave the department to return after 3½ hours. (See section ‘What will happen at my appointment?’)

        Do I need to stop my medication?

        If you have had a CT scan with contrast or you are taking any of the following medication please contact the Nuclear Medicine Department.

        • Thyroxine (T4).
        • Amiodarone.
        • Iodine containing supplements.
        • Triiodothyronine (T3).

          What will happen at my appointment?

          When you arrive for your appointment, you will firstly have a cannula put in and given a small injection of a radioactive liquid into a vein. This is usually in your arm or the back of your hand. This injection should not have any effect on you, but will allow us to take images using a gamma camera. The radioactive tracer will emit gamma rays which will be detected by a piece of equipment called a gamma camera.

          Following the injection there will be a delay of 3½ hours while the tracer accumulates in the thyroid. Upon your return you will be required to drink 2 cups of water in order to wash out any tracer from the salivary glands and oesophagus.

          For your scan you will be required to lie still on your back on the imaging bed, with a gamma camera positioned above you, but open at both sides whilst 2 images will be acquired. This should take 15 minutes.

          All images will be checked before you leave the department. Occasionally images may be repeated or extra images acquired if necessary.


            Do I need to undress for the scan?

            You will be asked to remove any metallic objects, such as a phone, keys and necklace. You may also be asked to change into a gown.

              What happens after my appointment?

              After the appointment you can resume all usual activities. Eat as normal and keep well hydrated.

              If you have young children or pregnant friends/family please limit close contact with them for 2 hours after the injection. You can be in the same room but avoid sitting close to each other for long periods. This is to avoid them receiving any unnecessary radiation exposure.

                When will I get my results?

                The report will be sent to your referring doctor. They will contact you to discuss the results. If you have any enquiries regarding your results please contact the department where the referral was originally made.

                  Are there any risks with this procedure?

                  The radioactive tracer administered will expose you to a small amount of ionising radiation.

                  The risks from this radiation are very low and the benefits of having the results from the thyroid scan greatly outweigh the risk.

                    Contact details

                    Royal Sussex County Hospital (RSCH)
                    Nuclear Medicine Department
                    Hanbury Building, Royal Sussex County Hospital, Eastern Road, Brighton BN2 5BE.
                    Telephone: 01273 696955 Extension: 64381 or 64382.

                    Princess Royal Hospital (PRH)
                    Imaging Department
                    Nuclear Medicine Department, Lewes Road Haywards Heath West Sussex RH16 4EX.

                      This information is intended for patients receiving care in Brighton & Hove or Haywards Heath.

                      The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.

                        Publication Date: June 2022

                        Review Date: March 2025

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