Question

What is the purpose of contrast in CT scan?

• A. ( \text{To suppress particular tissues} ) \
• B. ( \text{To enhance a particular tissue} ) \
• C. ( \text{To ensure correct tissue is being imaged} ) \
• D. ( \text{To reduce bone interference} ) \

Hint:

Contrast agents in medical imaging work by altering the way X-rays (in CT) or magnetic fields (in MRI) interact with specific body tissues, thereby increasing the visual difference (contrast) between various structures or between healthy and diseased tissue.

Answer 1

The Correct Option is B

In a CT (Computed Tomography) scan, contrast agents are substances administered to the patient to improve the visibility of specific tissues, organs, or blood vessels that might otherwise be difficult to distinguish from surrounding structures on a standard CT image.
The contrast agent typically contains elements with high atomic numbers (like iodine or barium) that absorb X-rays more effectively than body tissues.
When distributed within a specific area (e.g., blood vessels, liver, kidneys, or gastrointestinal tract), they increase the X-ray attenuation of that area, making it appear brighter on the CT images.
This enhancement allows for better visualization of pathological conditions such as tumors, inflammation, or vascular abnormalities.
It is not used to suppress tissues, ensure correct tissue imaging (which is done by patient positioning and scan protocols), or directly reduce bone interference (though it can help differentiate soft tissue from bone).