A CT aortogram (or CT angiography of the aorta) is a rapid, highly detailed scan used to check the aorta, which is the largest blood vessel in your body. The aorta carries blood from your heart down through your chest and abdomen to feed the rest of your organs.
If you present with severe, sudden chest or back pain, a CT aortogram is used to check for life-threatening issues, such as a bulging artery (aneurysm) or a tear in the blood vessel wall (aortic dissection).
Common Indications for a CT Aortogram
- Investigating sudden, tearing chest or back pain.
- Screening for or monitoring a known abdominal or thoracic aortic aneurysm.
- Evaluating a suspected tear (dissection) or blockage in the aorta.
- Checking for injuries to the aorta after a major accident or trauma.
- Planning surgeries or stent placements on the aorta.
What exactly does a CT aortogram show?
The scan shows a three-dimensional view of the entire path of your aorta. By using contrast dye, it highlights the thickness of the blood vessel walls, the size of any bulges, and any narrow areas or blockages.
How should I prepare for a CT aortogram?
You must fast (no food or drinks except water) for at least 4 hours before the scan. This is because the scan requires an injection of contrast dye, which can cause mild nausea. Drink plenty of water before the fast to remain well-hydrated, which protects your kidneys.
Do I need to stop taking medication?
Generally, you do not need to stop medications. However, if you have diabetes and take metformin, you may need to stop taking it for 48 hours after the scan to protect your kidneys. Confirm this with your referring doctor.
What happens when I arrive for my scan?
You will change into a gown and remove all metal objects, jewelry, and belts. A nurse will insert an intravenous (IV) line into a vein in your arm. They will check your kidney function using a recent blood test to ensure your kidneys can safely filter the contrast dye.
How is the procedure performed?
You will lie flat on your back on the scanner table. The table will slide slowly into the doughnut-shaped CT scanner. The scan team will leave the room but can see and hear you. During the scan, contrast dye is injected rapidly through your IV. You will feel a sudden wave of warmth and a metallic taste in your mouth. The table will move through the scanner as images are taken. You may be asked to hold your breath for 10 to 15 seconds.
How long does a CT aortogram take?
The actual scan takes only about 10 to 15 seconds. However, the preparation, IV insertion, and post-scan observation take about 30 to 45 minutes.
Is there any discomfort?
The scan itself is painless. You will feel a brief pinch from the IV needle. During the contrast injection, you will feel a warm flushing sensation throughout your body and a strong feeling that you have wet yourself (this is a normal sensation caused by the dye and passes quickly).
Are there risks?
Yes. There is a small risk of kidney strain from the contrast dye, especially in patients with existing kidney disease. There is also a very small risk of an allergic reaction to the dye. The scan uses radiation, which is kept to the minimum dose required for diagnostic accuracy.
Can children have this scan?
Yes. Children with congenital vascular conditions can have this scan safely. The team adjusts the radiation and contrast doses based on the child's weight.
Can I have this scan if I am pregnant?
Pregnancy Precaution
Tell your doctor or radiographer if you are pregnant or think you might be. Because this scan uses X-rays directly over the chest and abdomen, it is avoided during pregnancy unless there is a life-threatening emergency, such as a suspected aortic dissection.
When will I get my results?
A radiologist will study the images. A report will be sent to your referring doctor or handed to you within a few hours. In emergencies, the results are ready within minutes.
What if the scan finds something?
If the scan detects an aneurysm or dissection, your referring doctor will discuss management immediately. A large aneurysm or dissection may require urgent surgery or a stent placement, while smaller aneurysms are monitored with regular scans.
Conclusion
A CT aortogram is a vital, rapid tool for detecting aortic conditions. Remember to fast for 4 hours, drink plenty of water before fasting, and tell the team about any kidney issues or metformin use.