CT Colonography: A Vital Tool for Early Detection of Bowel Cancer
When it comes to preserving your health, early identification is often the best defence. This is certainly the case for bowel cancer, which in the UK is still among the most common cancers. The good news is that medical imaging has come on in leaps and bounds in the last few years, and the best test we have to spot early signs of bowel cancer is a CT colonography.
CT colonography (also known as virtual colonoscopy) is a non-invasive scan that uses advanced CT (computed tomography) imaging to create multiple pictures of the inside of the bowel. It is particularly helpful when a traditional colonoscopy is not feasible or has eviscerated to offer a clear outcome. In this post, we investigate what CT colonography is, when you might have one, and the role it plays in diagnosing bowel cancer.
What is CT Colonography?
A CT colonography is a type of medical imaging that enables doctors to see the colon and rectum in great detail without passing a camera into the bowel, as in a standard colonoscopy. It does so instead with low-dose X-rays that are used to produce a series of images that are digitally assembled to form a three-dimensional image of the colon.
It is conducted in a CT scanner, and the entire process generally takes approximately 20 to 30 minutes. A slender tube is carefully placed in the rectum to put gas (carbon dioxide or air) into the colon to puff it up, so the doctor can see the inside more clearly. No sedation is necessary, and most patients can return to usual activities the same day.
When is CT Colonography Used?
CT colonography is of particular value in several clinical scenarios:
- When colonoscopy is infeasible: Some people may be unable to undergo a standard colonoscopy because of medical conditions, age, or other risk factors.
- If colonoscopy is incomplete: If a colonoscopy is initiated but the length of the colon can’t be fully visualised—perhaps because of a blockage, the passage of scar tissue, or a patient being too uncomfortable—a CT colonography is a good option.
- In the context of asymptomatic bowel cancer screening: In specific circumstances where patients are unwilling or unable to have a colonoscopy, CT colonography has been advised as a non-invasive alternative for bowel cancer screening.
According to the UK government’s advice, CT colonography is a well-established diagnostic method which forms part of the NHS Bowel Cancer Screening Programme and is regularly applied in this manner to those aged 55 and over.
Benefits of CT Colonography
Reasons to trust CT colonography to investigate the bowel: Here are a few good ones:
Non-Invasive and Comfortable
- Unlike standard colonoscopy, CT colonography does not require a long camera to be inserted into the bowel, which some people may find uncomfortable. It’s typically less painful, requiring no anaesthesia or recovery time.
Quick and Efficient
- The whole scan takes usually under half an hour to perform with little downtime. For busy patients or anyone who wants to avoid missing work for a doctor’s visit, it could be ideal.
High-Resolution Imaging
- The images show detailed, 3D views of the colon, and the radiologist can easily check for polyps, abnormal growths, or cancer on the images.
Safe and Low-Risk
- A CT colonography is associated with the use of low-dose radiation, and its risk of complications is much lower relative to that of colonoscopy. There is no chance of bowel perforation, a rare but possible complication of a standard colonoscopy.
Are There Any Limitations or Risks?
If you’re considering CT colonography, keep in mind the following: Although reasonably accurate, CT colonography is not flawless.
- Taking biopsies is not an option during scanning. If something is found that looks suspicious, you may still need a regular colonoscopy to get a tissue sample.
- Radiation exposure is low—however, that dose is extremely low, low enough to be safe for almost all patients.
- It still takes preparation. As with a colonoscopy, you will need to adhere to a bowel preparation regimen to empty your colon before the scan. This typically involves taking a laxative and drinking a contrast material.
The Importance of Early Detection
Bowel cancer is the fourth most common cancer in the UK and the second largest cancer killer. But when caught early, it is highly treatable. Make sure you don’t ignore symptoms such as alterations in bowel habits, unintended weight loss, or pain in your belly or blood in your stool.
CT colonography can detect growths early—often before they present symptoms—enabling the most successful treatment and recovery for patients. It also provides peace of mind for those at heightened risk because of family history or older age.
For more information, read the UK Government’s information leaflet on CT Colonography.
What to Expect Before and After the Procedure
You will receive instructions on how to prepare your bowel before your appointment. That typically means a low-fibre diet and then a laxative which will empty the colon so it can be imaged.
On the day of the scan:
- You’ll put on a hospital gown.
- A small tube will be put into your rectum by the radiographer to inflate the bowel.
- The scan is painless and is done with you lying on your back and side while images are taken.
- You may feel a bit bloated or gassy afterward, but that will subside. There is no sedation, so as soon as the procedure is over (which often only takes minutes), you can move on with your day.
Book Your CT Colonography Today
If you’ve been referred for a CT colonography or have bowel health worries, you should act fast. Early detection can save your life—and if done here, CT colonography provides a safe, comfortable, and accurate way to examine your colon’s overall health.
If you would like to find out more about this study or consult one of our team, please contact us.
👉 To learn more, visit the UK Government’s guide to CT Colonography
Chase Lodge Hospital: CT Colonography – Putting your health in focus.
