Radiology (Xray)

CT Cardiac

What is cardiac CT?Show [+]Hide [-]

  • C.T. stands for Computerised Tomography and is a special type of x-ray that can look at various parts of the body including the brain, spine, chest, abdomen and pelvis.  Cardiac CT is an x-ray examination of the heart, which cannot be seen clearly on a normal x-ray of the chest. The information from the x-rays is recorded in a series of cross sectional pictures or scans that can be built up into a three dimensional image of the area being examined.

Who performs the scan? Show [+]Hide [-]

  • The person who carries out the scan is called a radiographer (a health professional trained to perform imaging procedures). They will explain the procedure to you and show you how to position yourself on the scanner table.

Why do I need a cardiac CT scan? Show [+]Hide [-]

  • Your doctor has referred you for this test to try and find out what may be causing your symptoms.

Do I need any special preparation before the examination?Show [+]Hide [-]


You must not eat or drink anything containing caffeine (e.g. coffee, tea, coca cola, chocolate) for 12 hours before your appointment. Caffeine can increase the heart rate and make it difficult to see the heart vessels clearly.

  • If you are taking isosorbide mononitrate or dinitrate tablets, you should stop taking them 12 hours before your scan.
  • If you normally wear a glyceryl trinitrate (GTN) skin patch, please phone the appointments help-line for the hospital you are due to attend, and we will advise you about this.
  • If you have your own glyceryl trinitrate spray please bring this with you. We may ask you to take this just before the scan starts in order to open up the heart vessels. We will ask you to take this if it is needed.
  • If you take beta blocker tablets, please continue to take these as normal on the day of the scan.
  • You can continue to take any other medication prescribed by your doctor. If you are unsure about any of your medicines please contact the appointments help-line for advice.
  • If possible, try to leave personal valuables at home when attending for your scan.

I am diabetic. Does this change anything?Show [+]Hide [-]

  • The preparation for your procedure is the same. However, if you take metformin please read the information below. You can take all other diabetic medications as normal.  If you have any concerns or queries regarding your diabetes, please ring the appropriate appointments/help-line telephone number at the hospital you are attending, and speak to a member of staff who will be able to advise you.

I take metformin tablets. Does this change anything?Show [+]Hide [-]

  • Yes.  Metformin is most commonly taken by diabetic patients to control blood sugar, but occasionally is taken for other conditions. If you have problems with your kidney function we may ask you to stop taking metformin for 48 hours after the examination. The staff will advise you about this when you attend for your examination.

I take sildenafil (Viagra) tablets. Does this change anything?Show [+]Hide [-]

  • Yes. In order to improve the quality of the CT scan we usually give a dose of glyceryl trinitrate (GTN) spray under the tongue; however glyceryl trinitrate is not normally given if you have recently taken sildenafil or similar medicines (avanafil, tadalafil or vardenafil) for erectile dysfunction. If you are taking any of these medicines for erectile dysfunction, please avoid using them for 24 hours before your test (48 hours for tadalafil).  If you take these medicines for any other reason, please keep taking it as normal and call the help-line number to inform us.

If I have problems with my kidney function, does this change anything?Show [+]Hide [-]

  • Yes. Depending on the scan you are having and how severe your kidney problems are, the preparation for your procedure may change. Please ring the appropriate appointments help-line telephone number at the hospital you are attending, and speak to a member of staff who will be able to advise you.

What if I am pregnant?Show [+]Hide [-]

  • CT scanning of pregnant women should be avoided whenever possible.  If you think you may be pregnant it is very important that you tell the radiographer before your scan.  To avoid accidental irradiation, all females between the ages of 11 and 55 years are asked the date of their last menstrual period.  From this information x-ray staff will decide if there is cause for the CT examination to be postponed, or if it is safe to continue.

What does the examination involve?Show [+]Hide [-]

  • When you arrive in the department a radiographer or assistant will ask you to change into a hospital gown.
  • For most cardiac CT examinations a radiographer will put a cannula into a vein in your arm to allow an injection of a colourless x-ray dye to be given during the scan. This helps to show up blood vessels and makes the scan easier to interpret.  The radiographer will have completed a check list with you, and asked you if you have any allergies or reactions to the x-ray dye.  If you have had a previous reaction to the x-ray dye, please ensure that you tell the radiographer before your scan.
  • The radiographer will show you how to position yourself on the scanner. It is important that you lie still for the duration of the scan.
  • Electrocardiogram (ECG) stickers/leads will be placed on your chest to allow the scan to start at the right time. The scan is timed with your heart rhythm.
  • You may be given an injection (occasionally tablets) of metoprolol (a beta blocker) to lower your heart rate in preparation for your scan. This allows us to see the heart vessels more clearly. If you are given metoprolol during your scan, you will have to stay in the department for at least 30 minutes after your scan has finished. Your blood pressure and heart rate will be checked before you leave the department.
  • We may also ask you to spray glyceryl trinitrate under your tongue just before the scan starts. This will help to open up the heart vessels.
  • You will be moved into the scanner and when you are ready we will give you some breathing instructions, and then your scan will begin.

How does it feel? Are there any side effects from the metoprolol, glyceryl trinitrate spray or x-ray dye?Show [+]Hide [-]

  • You should not experience anything to cause any discomfort from the injection of x-ray dye. However, it may give a warm sensation all over your body and a sensation like you are passing water. If you get these sensations, they will pass within 30 seconds. The radiographer will explain this to you when you attend for your appointment.
  • Glyceryl trinitrate spray can often cause an intense headache for a couple of minutes just after it is sprayed under the tongue. This should wear off very quickly.
  • Metoprolol is used to lower the heart rate to allow us to reduce the amount of movement of the heart and vessels during the scan. Beta blockers including metoprolol can lower your blood pressure as well as lowering your heart rate, which can very occasionally make you feel dizzy. We will take a blood pressure reading before we give you metoprolol to make sure that it is safe to proceed, and your heart rate and blood pressure will be taken again 30 minutes after the examination, to make sure that they have returned to the level that is normal for you before you leave the department.

How long will my scan take?Show [+]Hide [-]

  • The scan will take 20 to 30 minutes.

What happens after my scan? When will I get my results?Show [+]Hide [-]

  • After your scan has finished we will not be able to tell you the results as the reporting radiologist or radiographer will need to study the images carefully.  A report will be sent to the consultant or GP who requested the procedure. They should contact you when the results are available, or arrange a follow up appointment to see you.  If you are undergoing planned investigations on a ward, the result will be sent to the ward as soon as possible. The doctors on the ward may be able to discuss the findings with you.

Can I drive home? Show [+]Hide [-]

  • No. We recommend that you arrange for someone else to drive you home after your appointment. If you are given metoprolol during your examination it is advisable not to drive for four hours afterwards.

I need an ambulance/ transport. Do you arrange it?Show [+]Hide [-]

  • No.  If you need an ambulance/ transport, you should ask your GP Surgery to arrange it. You will need to give them three working days’ notice.  Please note that hospital transport is provided on medical need only.

What are the benefits of having a cardiac CT scan?Show [+]Hide [-]

  • This examination will help us make the correct diagnosis so that you can be given the correct treatment.

What are the risks of having a cardiac CT scan?Show [+]Hide [-]

  • Like all x-ray machines, a CT scanner produces potentially harmful x-rays.  Modern equipment is designed to keep the dose to patients as low as possible.  If your doctor has asked for a scan, then they will have decided that the benefit of having the information that the scan gives, is greater than the risk of the small dose of radiation.  Since x-rays can harm unborn babies, if you are, or could be pregnant, please tell the radiographer before you have the scan.  This is very important.
  • For scans that need an injection of x-ray dye, it is usually injected under pressure using a special injector machine. This is to show the blood vessels and organs more clearly and to obtain the best quality images. A haematoma (bruising) can occur at the injection site.
  • X-ray dyes are extremely safe drugs but there is a small risk that the x-ray dye can leak out of the vein into the surrounding tissues during the injection. This is called extravasation. Although extravasation can cause some temporary discomfort, long term side effects are rare. If an extravasation occurs you will be given advice whilst in the department, and a doctor will examine your arm before you leave.
  • While the risks are considered very low, the potential side-effects of X-ray dye, regardless of age, include allergic sensitivity and kidney damage.

Can I still breast feed my baby if I have a cardiac CT scan?Show [+]Hide [-]

  • You should plan for the need to avoid breastfeeding your child for 24 hours after the scan. Depending on which medicines we need to give you during the scan this may not be necessary, but we will not be able to determine that until the scan takes place.
  • You should express and store enough breast milk before the scan to feed your child for 24 hours. After the scan, if we advise you to avoid breastfeeding you should express and discard your milk for 24 hours and use the stored milk. After this time you can continue feeding your child as normal. If you do not express milk prior to the scan, your child will need to be fed with formula milk for 24 hours. It is important to speak with your midwife, health visitor or physician before making any decisions about stopping or interrupting breastfeeding.
  • If you think this will be a problem for you and your baby, or if your baby has any health problems, please contact the x-ray appointments helpline to discuss this before your appointment is due.

Can I still breast feed my baby if I have a CT scan with glyceryl trinitrate (GTN) spray? Show [+]Hide [-]

  • Yes. In most cases you can continue to breastfeed. Although the manufacturers recommend that breastfeeding is avoided if using GTN, this is because of a lack of research data available for breastfeeding mothers. However with the single doses of GTN that we give during this scan, we do not expect this to have any harmful effect on a healthy breastfed infant. If your baby is premature or has any health problems please contact us or ask your baby’s doctor for advice.

Can I still breast feed my baby if I have a CT scan with metoprolol?Show [+]Hide [-]

  • No. Manufacturers recommend that breastfeeding is avoided if using metoprolol, and this is because of a lack of research data available for breastfeeding mothers.

Can I still breast feed my baby if I have a CT scan with an injection of x-ray dye?Show [+]Hide [-]

  • It is not necessary to stop breastfeeding after an injection of x-ray dye. Although the dye enters your bloodstream directly, only a small proportion (less than 1%) is excreted into the breastmilk, which is safe for infants.
  • While the risks are considered very low, the potential side-effects of X-ray dye, regardless of age, include allergic sensitivity and kidney damage.

What if I cannot attend for my appointment? Show [+]Hide [-]

  • If your appointment time is not convenient please contact the hospital department so that a more appropriate time can be arranged.  This will enable us to reallocate valuable scanning time to someone else:
  • RVI X-ray Appointments               0191 282 4330 (Monday to Friday 8.30am-5.00pm)
  • Freeman X-ray Appointments     0191 223 1012 (Monday to Friday 8.30am-5.00pm)

What if I have any questions, suggestions or complaints?Show [+]Hide [-]

  • Should you have any suggestions or concerns, please make these known to the person conducting your examination or by letter addressed to the hospital that you are attending your examination:
  • The Departmental Manager, X-ray Department, Level 3, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP
  • The Departmental Manager, Main X-ray Department, Freeman Hospital, High Heaton, Newcastle upon Tyne, NE7 7DN
  • Tel: 0191 282 1099
  • Monday to Friday 8.30am to 5.00pm
  • All Newcastle Hospitals: Switchboard tel: 0191 233 6161 (24 hours)
  • The Patient Advice and Liaison Service (PALS) can offer on-the-spot advice and information about the NHS. You can contact them on freephone 0800 032 02 02 or email
  • Information produced by Sharon Iles, Superintendent Radiographer and Dr Anna Beattie, Consultant Radiologist.

Diagnostic Imaging DatasetShow [+]Hide [-]

  • Information from your diagnostic test will contribute to the Diagnostic Imaging Dataset. 
  • The Diagnostic Imaging Dataset (DID) is a database that holds information on the imaging tests and scans carried out on NHS patients. This will allow the Health and Social Care Information Centre to see how different tests are used across the country.
  • Nothing will ever be reported that identifies you.  All information is stored securely. It is only made available to appropriate staff, and is kept strictly confidential. However, if you do not want your information to be stored in the DID, please tell the people who are treating you. They will make sure your information is not copied into the DID.
  • You may, at a later date, still decide to opt out.  Please contact the Health and Social Care Information Centre directly, their contact details are:
  • Telephone: 0845 300 6016 
  • Email: 
  • Website:
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