CAMRT Radiography Practice Exam

Which type of imaging technique is likely unable to biopsy or remove polyps in the colon?

1. Conventional endoscopy

2. CT colonography

3. MRI

4. X-ray

The correct answer is: CT colonography

CT colonography, also known as virtual colonoscopy, is primarily a non-invasive imaging technique used to visualize the colon and rectum. It is effective for detecting polyps and other abnormalities but does not allow for direct intervention such as biopsies or the removal of polyps while imaging is performed. The nature of CT colonography relies on the use of CT scans to generate images of the colon after the introduction of air or carbon dioxide for enhanced visibility, but the procedure is diagnostic only, meaning it cannot provide therapeutic options during the imaging process. Conversely, conventional endoscopy allows for both visualization and direct intervention. During this procedure, polyps can be seen and removed in real-time. MRI is generally not used for colon imaging in the context of polyps or biopsy, but it is valuable for imaging other types of gastrointestinal conditions. X-ray imaging, while it can provide some information about the colon, lacks the resolution and specificity necessary for detecting and treating polyps.