CT Coronary Angiography

What is it

A CT coronary angiography is an imaging test used to examine the blood supply through your coronary arteries. Using a specialised CT scanner, it is able to pick up detailed images of your heart from different angles of which we are able to see on a monitoring screen. This imaging test is able to clearly pick up images of your heart because an iodine-based dye would have been injected in to your blood stream from your arm prior to this investigation. The way the dye works is when it enters your blood stream it highlights your blood vessels helping the CT scanner pick up the imaging much more clearly. You may also be asked to take medication which will help your heart slow down.

Why is it done?

The primary reason of why you would need to have this imaging test is to check your heart variations and condition. Often, if patients are experiencing symptoms from conditions such as coronary heart disease and have not yet been diagnosed, this test will be used to identify any abnormal activity in the heart.


Preparation for this scan is pretty simple. You will be asked not to eat or drink anything accept water for about 4 hours before the test. Caffeinated drinks are not to be drunk for 12 hours before the test, this is because they speed up the function of the heart and will not give the CT scan a correct reading of your heart.

You will need to remove all metal from your person and you will be given a gown to wear during the imaging test.

Your doctor will always explain to you in detail how you need to prepare prior to the test. Make sure you ask if you are unaware or have forgotten.

What happens during the imaging test?

Before the test your doctor may have given you a beta blocker to slow down your heart. An iodine-based dye will be injected in to your arm and will enter the blood stream which will make your hearts arteries visible during the test.

The radiologist will place stickers on your chest, they are called electrodes and are connected to an echocardiogram. This will monitor your heart rate during the procedure.

You will lay down on a scanning table, it will move quickly through the scanner to determine the correct position to perform the scans. The scanner will slowly move and take images of your heart, whilst it is doing this you may be asked to hold your breath for short intervals to optimise picture quality. The procedure will take up to 15 minutes in total.


A radiologist will review the images and write a detailed report of the findings. This will be passed back to the consultant along with the images on a digital screen. The doctor will interpret and compare the report with the images on the screen to find a diagnosis. You will be asked to attend an appointment where your doctor will talk you through the exam findings and discuss the next steps.

This article is intended to inform and give insight but not treat, diagnose or replace the advice of a doctor. Always seek medical advice with any questions regarding a medical condition.