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Department of Nuclear Medicine
What is this information about?
This information is about your SeHCATTM scan.
Why have I been given this information?
You have been given this information because your doctor has referred (sent) you for a SeHCATTM scan.
Reading this information can help you to know what to expect from your scan. Following the advice will help to make sure that the scan goes as well as it can.
What is Nuclear Medicine?
Nuclear medicine:
- is a safe and painless technique which provides medical images of the body.
- uses small amounts of radioactive materials as tracers to diagnose or treat disease. In diagnosing a condition, the radiation is detected by a special type of camera called a “Gamma camera”.
What is a SeHCAT scan?
A SeHCATTM (pronounced ‘see cat’) scan shows how your body processes bile salts. Bile salts help the body to digest fats from your diet.
If your bile salts are not being reabsorbed (taken into your body) through the small bowel correctly, it can lead to diarrhoea which keeps coming back. This is called ‘bile acid malabsorption (BAM)’
Be aware
You will need to book two appointments, 7 days apart.
What can I expect during my appointment?
- Day one, you will be given a small radiotracer capsule to swallow that contains a synthetic bile salt. You can then leave the department.
- Day seven, you need to return to the department for the SEHCATTM scan. The scan takes 10 minutes.
- While you are having the scan you must lie as still as you can on a ‘table’ while a camera moves over and under your body. The camera will not touch you and you will not be in a ‘tunnel’.
Where should I go for my scan?
You will have your scan in the Nuclear Medicine Department, St Richard’s Hospital.
Use the main entrance to the Outpatients Department. This is in the South Wing of the hospital.
Once you are inside the Outpatients Department, turn right and take the stairs or lift to the Department of Nuclear Medicine on the first floor.
Wheelchairs are available just inside the entrance on the ground floor.
If you are arriving by car, please use hospital entrance number 2.
If you need to park, use the ‘pay on foot’ car park close to the entrance to the Outpatients department (South car park). Pay at the end of your parking session using the machines in the Outpatients department entrance. Disabled parking bays are available for the registered disabled near the main Outpatients’ entrance.
How can I prepare for my SeHCAT scan?
- Eating and drinking. You can eat and drink as usual before the scan appointment.
- Medications. If you are taking any of the following medications, you will need to stop them before the test:
| Drug | Type | Stop before test |
|---|---|---|
| Cholestyramine (Questran) | Bile acid chelates | 5 days |
| Colesevelam (Cholestagel) | Bile acid chelates | 5 days |
| Colestipol (Colestid) | Bile acid chelates | 5 days |
| Loperamide (Imodium, dioraleze) | Anti-diarrhoea | 2 days |
| Co-phenotrope | Anti-diarrhoea | 2 days |
| Codeine | opiate | 2 days |
| Morphine | opiate | 2 days |
| Amitriptyline | Tricyclic antidepressant | 7 days |
| Aluminium hydroxide | antacid | 5 days |
Might I have an allergic reaction to the radioactive injection?
Allergic reactions to the radiotracer are very rare but can happen. Please note the capsule contains gelatine made from animal products.
Can I have a SeHCAT scan if I am pregnant?
We will check your pregnancy status with you before the scan. If you are, or think you may be, pregnant you must tell us as soon as possible.
Will I need to undress for my scan?
We recommend that you wear comfortable, loose clothing. Usually, you do not need to undress for your scan. You may need to remove items such as belt buckles, jewellery and other items of clothing with metal in them.
What should I do if I cannot come to my appointment?
You must let us know as soon as possible if you are unable to attend. This is so that we can offer the appointment to someone else.
Be aware,
it is Trust policy that you will not be offered a further appointment if you do not attend a booked appointment.
This means that you will need to return to the doctor who referred you for the scan.
How long will the scan take?
SeHCATTM scans take 10 minutes. This does not include the 7-day delay between your capsule and the scan.
Who will be at my scan?
A radiographer or an assistant practitioner will be with you in the room during the scan.
There are students training in the scanning department. A qualified radiographer will supervise them if they do your scan. Please tell us if you would prefer not to have a trainee at your scan.
Are there any risks?
We are all exposed to natural background radiation every day. This comes from the ground, building materials around us, the food we eat and from the sun.
This scan will give you a small extra radiation dose on top of this. The amount depends on the type of scan you are having. It ranges from a few days’ natural background radiation to a few years.
After weighing up the risks and benefits your doctor has decided that having the scan is right for you. They believe that the potential benefits outweigh the risk.
The radiation dose for the scan is listed in the table below, along with a comparison of radiation doses from other sources of radiation.
The only effect known at these low doses is a very small increase in the chance that you might get cancer many years or even decades after the exposure.
The additional cancer risks from these different sources of radiation are shown in the table below.
These risk levels are a very small addition to the 1 in 2 chance we all have of getting cancer at some point during our lifetime.
| Radiation Source | Radiation Dose | Lifetime additional risk of cancer per examination | Risk |
|---|---|---|---|
| Chest X-ray | 0.014 mSv | 1 in 1,350,000 | Minimal |
| Transatlantic flight | 0.08 mSv | 1 in 250,000 | Minimal |
| UK average annual radiation dose | 2.7 mSv | 1 in 7,500 | Low |
| SeHCATTM scan | 0.3 mSv | 1 in 66,000 | Very Low |
| Chest CT | 6.2 mSv | 1 in 3,200 | Low |
Can I drive home after my scan?
Yes.
When will I get my scan results?
The results will be sent to the doctor who asked for the examination and will usually be with them within 2 weeks. If you have an appointment sooner than this then please let us know so we can make sure the results are provided in time.
Can I bring someone else with me to my appointment?
Yes. You can bring someone, such as a friend, relative or carer with you. They must be over the age of 16
Be aware
You may not bring children under the age of 16 or pregnant people with you to your appointment. There is no child-minding service at the Trust. You must make your own arrangements for childcare while you are having your appointment if you need to.
To protect other people from radiation, after you have had your radiotracer injection, plan to keep a distance of at least 1 meter from them until the end of the day. For further advice please contact the Nuclear Medicine Department.
How is my medical data protected?
Everyone working within the NHS has a legal duty to keep patient information about you confidential & secure. If you have any concerns around the use of your medical and diagnostic imaging information, copies of the “Care Record Guarantee” and “Your Medical Data” leaflets can be downloaded from:
UHSxYou can get a printed copy of these leaflets from the PALS (Patient Advice and Liaison) office at Worthing or St Richard’s, Chichester, Hospitals.
Who can I contact if I need further information or support after I have read this information?
For further general information on Nuclear Medicine and SeHCAT™ scans
If you have questions or need further information about your SeHCAT™ scan appointment, please contact the Nuclear Medicine Department (staffed Monday to Friday):
Nuclear Medicine Department,
St Richard’s Hospital,
First floor, Outpatients block (South Wing)
I need help with transport to my appointment for medical or financial reasons. What help is available?
To find out what help with transport you may be able to get please visit the
- To enquire about booking the hospital transport service phone
- To check whether you can get help with the cost of transport, phone the St Richard’s Hospital switchboard 01243 788122 and ask for the Cashiers Office.
Hospital transport service
0300 777 4444
St Richard’s Hospital switchboard
01243 788122
Be aware
You should do this before your appointment.
This leaflet is intended for patients receiving care in St Richard’s Hospital.
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.
Today’s research is tomorrow’s treatments. That’s why UHSx is proud to be a research-active Trust. Find out how you can get involved.
Visit our website www.uhsussex.nhs.uk/research-and-innovation/information-for-patients-and-public or scan the QR code: 