What is the Most Common Reason for a CT Scan?
A CT scan, or computed tomography scan, is a type of scan that uses X-rays and computer technology to create cross-sectional images of the inside of your body.
Unlike an X-ray, which captures 2D images of your bones, a CT scan uses X-ray technology to capture detailed 3D images of your tissues. It is, therefore, used to investigate a range of symptoms caused by disease and injury.
Here, we will discuss the most common reasons for needing a CT scan and how to prepare for your CT scan appointment. We will also explore how a CT scan works, different types of CT scan and what happens after your private CT scan.
Common Reasons for a CT Scan
A CT scan captures images of your organs, muscles, blood vessels, bones, cartilage and soft tissues, such as tendons and ligaments. Consequently, it can be used to help diagnose a variety of conditions.
It can investigate injuries such as broken bones and internal bleeding. CT scans are also used to investigate abnormal growths, which can be cancerous or non-cancerous (benign) tumours.
A CT scan can assess the health of your organs too. For example, a CT scan of your kidneys can help determine whether you have kidney stones, kidney abscesses or kidney disease.
A CT scan of your bowel can help determine whether you have bowel conditions, such as diverticulitis, Crohn’s disease or appendicitis. A head CT scan can help detect brain tumours or assess whether you have had a stroke and how severe it was.
A special kind of CT scan called a CT coronary angiogram can be used to assess your hearts’ health by imaging the blood supply to your heart. This can help detect coronary artery disease, aneurysms and blood clots.
CT Scans in Emergency Situations
CT scans are often used in emergency situations because they provide highly detailed images quickly. This is in contrast to MRI scans, which also produce highly detailed images but do so more slowly.
Emergency situations where a CT scan may be used include having a brain CT scan immediately after a stroke or head trauma, or an abdominal CT scan after trauma to the abdomen to check damage to internal organs.
Types of CT Scans
As mentioned earlier, CT scans can be used to investigate a wide variety of health conditions. Consequently, they can be grouped according to the part of the body being scanned.
Cardiac CT scans image the heart and include CT coronary angiograms and CT calcium scores. During both types of cardiac CT scans, you will also have leads attached to your chest to measure your heartbeat using an ECG machine.
A CT coronary angiogram uses a contrast agent to image the blood vessels carrying oxygen-rich blood (arteries) that supply your heart. The contrast agent is given through a small tube (cannula) inserted into a vein in your arm.
A CT calcium score measures the amount of hardened fatty deposits (plaques) in the arteries that supply your heart. This does not use a contrast agent.
Other CT scans include a chest CT, head CT, sinus CT, bone CT, kidney CT, spinal CT, pelvic CT and a CT colonography. A CT colonography is also known as a virtual colonoscopy and captures images of the bowel.
A CT scan can also be performed at the same time as a positron emission tomography (PET) scan. A PET scan involves injecting a safe radioactive dye into a vein, which is imaged as it moves through your body. A PET-CT scan is most often used to help diagnose cancer and track its progress.
How to Prepare for a CT Scan
Your care team will advise you on how to prepare for your CT scan. Their advice will depend on which part of your body is being scanned and whether or not you will need to have a contrast agent to improve the clarity of the images captured.
In general, if you have a contrast agent, you will be asked not to eat or drink for several hours before your scan. If you have diabetes, you will be asked to have a lighter meal than usual and to bring food and your insulin to your appointment.
On the day of your CT scan, make sure you wear loose, comfortable clothing that does not contain any metal eg zips, clasps, bra underwires, etc. Also, make sure you do not wear any metal jewellery or hair accessories. This is because metal can reduce the quality of the images captured by causing streaks to appear.
When you arrive for your CT scan, you will be asked to fill in a health questionnaire. This will help assess whether you are at risk of an adverse reaction to the contrast agent that may be used during your CT scan.
What Happens During Your CT Scan?
A CT scan is a safe, non-invasive imaging technique that usually takes 10-30 minutes to complete depending on which part of your body is being scanned.
Before your scan, you may be given a contrast agent, which is a special dye to help create clearer images during your scan. The part of your body being scanned will determine how the contrast agent is given ie whether it is injected into a vein, swallowed as a liquid or administered as an enema via your back passage (rectum).
Different medical scans use different contrast agents. For CT scans, an iodine-based contrast agent is used. It is a clear liquid and will not stain or dye your internal organs.
However, the contrast agent does make it harder for X-rays to pass through your body. This means parts of your body containing the contrast agent, such as your blood vessels and organs, will appear brighter on your CT scan images.
After having your contrast agent, you will be asked to lie flat and still on the scanner table. The table will then be passed into the ring-shaped structure of the CT scanner.
The ring will rotate around your body and release narrow beams of X-rays. The X-ray beams will pass through your body and will then be detected by sensors contained within the ring-shaped part of the CT scanner.
These signals will be sent to a computer where they will be processed to form an image of a complete slice through your body. As the scanner table moves through the ring, another image slice will be captured.
Unlike an MRI scan, the CT scanner will not make any loud noises as it scans your body. Once your scan is complete, the image slices are stitched together to create a 3D image of the inside of your body from all angles.
At certain points, your radiographer – the healthcare professional who will be administering your CT scan – may ask you to momentarily hold your breath. This is because the movements caused by breathing can sometimes interfere with the clarity of the images captured.
As tissues absorb X-rays in different amounts, different tissues within your body will appear as varying shades of grey. Bone will appear white, while gas and most fluids through which X-rays easily pass will appear black.
What to Expect after Your CT Scan
If you do not have a contrast agent for your CT scan, you can return to your usual activities straight away.
If you have a contrast agent, you will be asked to remain at the scanning facility for 30 minutes. This is to check that you do not develop an adverse reaction to the contrast agent. Most people are not allergic to the contrast agent used in CT scans.
If you have had an adverse reaction to the contrast agent used in an MRI scan, this does not mean you will have an adverse reaction to the contrast agent used in CT scans. This is because MRI and CT scans use different contrast agents. However, you should still inform your care team of your past allergic reactions.
At Vista Health, we aim to have your CT scan results ready within 3 working days. You will be sent a comprehensive report written by one of our experienced radiologists – a doctor who specialises in diagnosing and treating conditions using imaging technologies. This report can also be sent to your NHS GP.
Why Have a Private CT Scan
With a private CT scan, you can gain clarity over unexplained symptoms so you can make well-informed decisions about your health and wellbeing.
At Vista Health, you do not need a referral from a healthcare professional to book a private CT scan. This means less waiting so you can get to the bottom of your symptoms sooner.
Book Your CT Scan Today
Are you ready to enjoy the benefits of a private CT scan? Peace of mind when it comes to your health. Expert insights into any concerning symptoms. The information you need to make the right decisions for your health.
Then it is time to book your private CT scan today at one of our convenient, nationwide locations.