CT (Computed Tomography) Scan

CT (computed tomography) scan

During a CTCA an ultra-fast computed tomography (CT) scanner is used to examine the blood vessels that supply blood to the heart.

This scan involves injecting contrast through an arm vein highlighting the vessels.


It is important to ensure that no products containing caffeine are consumed 24 hours prior to your examination. This includes coffee, tea, chocolate, energy drinks and soft drinks.

It is also important to not take any medication for erectile dysfunction for 3 days prior to your examination.  All other medications can be taken as normal, on the day of the scan.

It is vital that patients are well hydrated for this scan and also fast from all food 4 hours prior to the examination time.

On the day of your appointment, it is important to arrive 45 min prior to your examination for a pre-exam assessment.

This pre-exam assessment will involve a Cardiac CT Radiographer and nurse monitoring your blood pressure and heart rate to determine if you require any beta-blocker medication (used to slow down the heart beat) before your scan. 

Your CTCA examination will be performed once the Radiologist is satisfied with your heart rate.

During Procedure

You will be given a full explanation of the procedure by the Qscan Radiographer performing your examination.  In most cases, you will be asked to change into a gown and have your blood pressure and heart rate monitored.

You will have a cannula (plastic needle) inserted in the vein near your elbow and an ECG lead placed on your chest.  GTN (Nitrolingual spray) is administered under the tongue just before the scan to dilate your coronary arteries, this will assist in obtaining the best images possible. The GTN may give you a mild headache.

You may notice a warm sensation and a metallic taste during the contrast injection. This is normal. For some scans you may also be asked to hold your breath for up to 15 seconds and to lie flat for about 10-20 minutes.

It is important to allow for post procedure care and monitoring for a short period of time after the completion of the examination.

The effects of beta-blockers should wear off after half a day but please consider organising someone else to provide transport home, especially if you live far away.


Timing will depend on the examination you are having. Although the scan time is very fast, the work up process is quite involved and it is recommended that you allow at least 2 hours for pre-examination purposes.