When Colonoscopy Isn’t Possible: Understanding CT Virtual Colonoscopy
Routine colonoscopies help detect colon cancer early and find polyps before they can turn into cancer. However, some patients may not be able to undergo a traditional colonoscopy. In these situations, a CT Virtual Colonoscopy may be considered as an alternative screening option.
What Is a CT Virtual Colonoscopy?
A CT Virtual Colonoscopy uses a low-dose CT scan (also called a Cat Scan) to capture 3D images of the large intestine. These images allow radiologists to evaluate the colon for polyps or other findings that may require follow-up. It’s quick, safe and does not require sedation.
Who May Be Considered for This Exam?
A CT Virtual Colonoscopy may be considered for patients who are unable to undergo or complete a traditional colonoscopy, including those who:
Take blood thinners or have an increased risk of bleeding
Have medical conditions or age-related concerns that pose risk from anesthesia
Were unable to complete a traditional colonoscopy in the past
What to Expect During a CT Virtual Colonoscopy
Before the Exam
To obtain the clearest images, preparation the day before the exam is required. This includes:
Following a clear liquid diet
Drinking a liquid laxative solution
Day of the Exam
- Fasting is required (no food or drink)
During the Exam
A small, flexible tube is placed in the rectum, and a small balloon is inflated to gently expand the colon
Patients are asked to lie in different positions on the CT table so images can be captured from multiple angles
The CT scanner takes detailed pictures of the colon
The entire process takes about 30 minutes.
After the Exam
Normal diet and activities can be resumed immediately
A companion is not required, though patients may bring someone if they wish
A radiologist will review the images and results will be shared automatically to the referring provider
Exploring Your Screening Options
Colonoscopy remains the standard method for colon cancer screening. If a traditional colonoscopy is not possible or cannot be completed, your provider may discuss whether CT Virtual Colonoscopy is right for you.
Contributor: Fernanda Mazzariol, M.D.