A virtual colonoscopy, also known as CT colonography, is a quick (10 to 20 minute), minimally invasive test that does not require sedation. Using X-rays and advanced imaging, the test creates detailed pictures of the colon that are reviewed by a radiologist. For many patients, this offers a more convenient and comfortable screening option.
The idea of a traditional colonoscopy can feel intimidating. Concerns about sedation, preparation, or taking time off work often lead people to delay or avoid screening. But skipping screening can be risky, especially as colorectal cancer rates continue to rise in younger adults. In recognition of Colorectal Cancer Awareness Month, Dr. Kevin Chang, Section Chief of Abdominal Imaging and Director of MRI at Boston Medical Center, shares what patients should know about virtual colonoscopies and how they offer a more comfortable screening option.
“Colorectal cancer is changing, and so must the ways we screen for it,” Dr. Chang says. Colorectal cancer is increasingly being diagnosed in younger adults and is now the leading cause of cancer death among Americans under age 50. Many younger patients are diagnosed at more advanced stages, which makes early screening especially important.
While common, colorectal cancer is highly preventable and treatable when caught early. Expanding access to screening options like virtual colonoscopy can help more people get tested sooner.
What is a Virtual Colonoscopy?
A computed tomography (CT) colonography, or a virtual colonoscopy, is a screening test that, like traditional coloscopies, is specially designed to look for bumps and polyps. This test is non-invasive, using X-rays and computers to produce images of the colon, which are reviewed by a radiologist.
What Happens During a Virtual Colonoscopy?
Most patients are scanned in two positions, on the back and stomach, using a CT machine. A CT scanner is a specialized imaging machine that uses low-dose X-rays to create detailed images of the body, including the colon.
What Preparation is Required for a Virtual Colonoscopy?
Before: You will need to complete a bowel preparation so the colon is clear for imaging. This usually includes a clear liquid diet and a laxative the day before the exam. The preparation is often less intensive than what is required for a traditional colonoscopy
After: Unlike a traditional colonoscopy, no sedation is used, so you do not need a ride home. You may return to work or otherwise continue your day.
Who Should Consider a Virtual Colonoscopy?
Generally speaking, patients who are of average risk of colon cancer should begin regular screening, such as a virtual colonoscopy, at age 45. Ask your provider if a virtual colonoscopy is right for you. Many insurance plans cover colorectal cancer screening as preventive care, but coverage may vary, so check with your insurer. A virtual colonoscopy is very good at detecting polyps or other changes in the colon, including those most likely to require treatment. If the scan finds a polyp, a traditional colonoscopy may be recommended so that the polyp can be removed during the procedure. The good news is that about 9 out of 10 people who receive a virtual colonoscopy will not require a follow-up appointment for a traditional colonoscopy.
Expanding screening options like virtual colonoscopies can help more people get tested earlier and prevent cancer before it starts.
Jennifer Davids, MD, the Chief of Colon and Rectal Surgery at BMC, knows that talking about signs and symptoms of colorectal cancer can feel taboo or embarrassing, especially for younger patients. But because of the rise of these cancers in younger generations, any more comfortable and still useful way of being screened is important.
“Often symptoms are attributed to stress or diet, or patients are afraid to come in for a variety of reasons,” she says. “Even among healthcare providers it’s thought of as an older person’s cancer, which is no longer the case. So, it’s important to get checked for symptoms and have a very low threshold to come in and get medical attention.”