CT Coronary Angiography

CT coronary angiography is a dedicated study investigating the arteries that supply the heart muscle. “CT” scan or “CAT” scan, stands for Computerised Tomography. It is a valuable diagnostic test that allows radiologists to see inside some areas of the body which cannot be seen using conventional x-rays.

Overview

Coronary CT angiography involves an injection of x-ray dye intravenously and the attachment of ECG leads to the chest.  The CT scanner is used to gather a series of images of the heart which are then reconstructed by a computer into cross-sectional views. From this our doctors can assess the status of coronary artery disease.

Coronary CT Angiography is provided at our sister practice Norwest Medical Imaging, located in Bella Vista.

Norwest Medical Imaging has one of the most advanced CT scanners available; the Aquilion One 320 slice, manufactured by Toshiba. Our scanner uses the latest software to ensure the lowest radiation dose possible.

Preparing for a Coronary CT angiography

Please bring your referral (letter from your doctor) and your Medicare and/or Pension Health care card with you to your appointment. It is important to bring all previous films and reports relating to the region being imaged.

You will be asked to fast for 4 hours (some water may be taken).

Stimulants, such as caffeine, should be avoided for 24 hours prior to the examination.

If you are diabetic and take Metformin (also known as Glucophage, Diabex or Diaformin), then you may be required to stop taking the Metformin on the day of your CT scan and the following 24 hours. It is best to bring recent blood test (renal function) results with you. All other medication should be continued.

Beta blockers may be required to reduce the heart rate for the scanner. These may be prescribed by your referring doctor or administered prior to the coronary CT angiogram if required.

You will be asked to sign a consent form and complete a medical history questionnaire.

You will be asked to change into a gown.

Scanning

Our highly trained radiographer will bring you into the CT scan room where you will be asked to lie down on the CT table.

The ECG will be connected to your chest to monitor your heart rate and a cannula is then inserted into a vein for the administration of contrast. A dose of nitrolingual spray under the tongue is given to dilate the arteries of the heart for accurate assessment. This spray is sometimes associated with a slight headache.

The radiographer is in full view and communication with you through the observation window at their console. The scanner does not touch you, nor do you feel the x-rays. The scanner does make a slight buzzing sound and the table you are lying on may move slightly to make adjustments for a better view.

The intravenous contrast is administered halfway through the Coronary CT Angiogram. It is normal to experience a warm flush over the body, a metallic taste in the mouth and a warm sensation in the bladder. These sensations are normal and cease after a couple of minutes.

It is important you lie very still and you will be asked to hold your breath as the images are acquired.

The procedure takes up to an hour to perform depending on your resting heart rate on arrival. You have no restrictions after having a CT scan and can go about your normal activities. To help eliminate the contrast medium from your body, drink plenty of fluids after the scan.

Results

The examination of the coronary arteries involves a detailed workup of the data obtained from the scan. This can take some time and hence the results will not be available on the day of examination. The results will be available in 48 hours from the scan. Any urgent situations encountered will be reported to your referring doctor on the day of examination.

Norwest Medical Imaging strongly advises that you return to your referring doctor, in order for your doctor to discuss your radiology report with you.

We understand that some patients are anxious about having tests performed. If you have any questions or concerns, please do not hesitate to ask our staff.

FAQs

Can I continue my medication before a Coronary CT Angiogram?
If you are diabetic and take Metformin (also known as Glucophage, Diabex or Diaformin) you may be required to stop taking the Metformin on the day of your CT and to have recent blood test (renal function) results with you. All other medications should be continued, especially beta blockers.

Why do I need to take beta blockers?
It is essential that your heart rate is between 60-70 beats per minute (bpm) to ensure the highest quality images with the lowest possible radiation dose.

What is the radiation dose for a Coronary CT Angiogram?
At Norwest Medical Imaging we follow the ALARA (as low as reasonably achievable) principle in regards to radiation dose. Our CT scanner uses the latest software to ensure the lowest radiation dose possible and our highly trained radiographers tailor the test to each individual patient.

How long will the Coronary CT Angiogram take?
The procedure can take up to an hour to perform depending on your resting heart rate on arrival. The scan itself takes 10-15 minutes.  Please enquire when you make your appointment.

Can I eat and drive after a Coronary CT Angiogram?
You have no restrictions after having a CT scan and can go about your normal activities. To help eliminate the contrast medium from your body, drink plenty of fluids after the scan.

Do I have to take my clothes off for my Coronary CT Angiogram?
You may be requested to change into a gown.

Will the radiographer performing my scan tell me what’s wrong?
The radiographer is not qualified to read your x-rays. It is the radiographer’s duty to perform the test and ensure the images are of high quality for the radiologist (specialist doctor) to interpret them.