Your nuclear medicine scan

Information for patients about nuclear medicine scans at North Bristol NHS Trust.

What is a nuclear medicine scan?

A Nuclear Medicine scan is a way of producing images that involves the administration of a small amount of radiation into your body. This radiation can be picked up by special cameras (gamma cameras) to make images that help your doctor diagnose and treat various medical conditions. 

Are there any risks from the radiation?

The amount of radiation involved is small. We can assure you that all efforts to minimise radiation are taken. The benefit to you of having the scan to help with a diagnosis will outweigh any risk from the radiation. Your referring doctor will have considered this carefully before asking us to carry out this examination.

Do I need to prepare for the scan?

Each type of nuclear medicine examination will have a different preparation. Please read your appointment letter carefully as it will specify what the preparation for your particular scan will be.

What is involved?

  • The isotope is usually injected into a vein in your arm but for some examinations it may be swallowed or breathed in the form of a gas. This depends on the type of examination being performed.
  • The injection of the radioactive substance is similar to having a blood sample taken. You will not feel any ill effects, drowsiness or sickness, and it will not affect your ability to drive a car.
  • For some examinations scanning begins immediately and for others there is a delay between the injection and the images. Some examinations have both immediate and delayed scans.
  • If there is a long period of delay between the injection and the scan you will be able to leave the department during this interval. This can be confirmed with the radiographer or technologist who will be looking after you.
  • During the scan you will have to keep still for periods of time, ranging from a few minutes, up to an hour.
  • You can normally leave your clothes on but we may ask you to remove any metallic objects.

What about breastfeeding?

Some of the radioactive substances are excreted in breast milk. Therefore, if you are breastfeeding it is important to contact us as soon as you receive your appointment letter. We will give you simple guidance about what to do beforehand and written instructions on the day of attendance. For the majority of scans there will be no need to stop feeding your child.

What if I am receiving renal dialysis?

Please ring us as soon as you receive your appointment letter if you are having renal dialysis. It may be necessary to alter the days you have your treatment to fit in with the scan.

What about caring for children and pets?

For most nuclear medicine examinations, we ask that you avoid prolonged close contact with children or pregnant women for some time following your scan.

If your scan requires specific instructions, these will be discussed with you on the date of the appointment. If you are the sole carer of small children, it may be advisable to ask someone to help you on the day of your examination. If this is difficult, please ring the department for advice. 

Your pets will not be affected.

What if I need someone with me?

You will be able to bring someone with you to the appointment (e.g., relative, friend or carer), provided they are not pregnant and are over 18 years old. Due to the radiation used for our scans, we may ask you to attend alone for some parts of the procedure. 

If you would like more information about having someone with you during your procedure, please call us in advance so that we can advise you further.

What if I can’t attend the appointment?

The radioactive injection required for this examination is ordered especially for you. If you are not able to attend, please let us know at least the day before your appointment to ensure that we have enough notice to cancel the injection or to allocate it to a different patient on our waiting list.

If I am taking tablets or other drugs, do I stop taking them?

For some nuclear medicine procedures, we may need to get a list of your medications to ensure that we obtain the best results possible, as some medications affect our scans. If the procedure you are scheduled for requires us to check your medication, this will be detailed in your appointment letter.

What if I am pregnant?

If you are or if you think you may be pregnant, please contact us before your appointment date by phoning 0117 414 1814. Becoming pregnant soon after a nuclear medicine scan is not a cause for concern.

Do I need to do anything after the scan?

When you leave the department after your scan you will be given information about the type of radioactive substance you have received and specific precautions to observe following the procedure. You should keep this with you following the scan in case you need to see a doctor or dentist for any reason in the time specified on the information sheet. You should show them the information before you receive any treatment.

We usually recommend you drink plenty of fluids and empty your bladder regularly as this will help your body to clear the radioactivity.

You may also need to avoid prolonged contact with children under 18 and anyone who is pregnant. If you are breastfeeding specific instructions will be given to you.

For most scans, it is advisable that you do not have a blood or urine test following the radioactive injection.

If your work involves close contact with other people and/or you are involved in radiosensitive work, we may advise you not to return to work until the day following your investigation.

It is very unlikely that you will feel any side effects after the scan, but if you do think that you have, please let the Nuclear Medicine department know.

Will I be able to travel abroad after the scan?

It is perfectly safe for you to travel abroad after your scan, but many airports and sea ports are now equipped with very sensitive detectors. Therefore, the very small amount of radiation left in your body could set off a detector as you pass through security. 

If you intend to travel abroad within the days following your appointment, please let the Nuclear Medicine department know, and additional documentation can be provided to you to facilitate your travel plans. 

How will I get the results?

The results will not be available at the time of your scan. The images will be examined in detail by a specialist doctor, who will issue a report. This will be sent to the doctor that referred you for the scan. You will hear about the results and any further care plans from their clinic. 

Further information

British Nuclear Medicine Society

Information for Patients and Carers.

British Nuclear Medicine Society

Public Health England

Information on Ionising Radiation Exposure of the UK Population.

Welcome to GOV.UK

Royal College of Radiologists

Information for Patients.

Homepage | The Royal College of Radiologists

NHS Constitution

Information on your rights and responsibilities

NHS Constitution for England - GOV.UK

© North Bristol NHS Trust. This edition published February 2025. Review due February 2028. NBT002025

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Your nuclear medicine scan