How Does a CAT Scan with Contrast Work?

Computed tomography  一 referred to as either a CT scan, a computerized axial tomography, or simple a CAT scan 一 is a specialized imaging test. CAT scans take two-dimensional (2D) projected images of the part of your body being examined, whether that’s soft tissues, organs, or blood vessels. Because CAT scans have the ability to produce cross-sectional images, these images are invaluable for diagnostic and treatment-planning purposes. 

If you need a CAT scan, Dr. Ebrahim Delpassand may recommend that you have one with contrast. Contrast is a special material that plays a big role in making your images even more clear and accurate.

Below, our team at Excel Diagnostics & Nuclear Oncology Center dives into the topic and explains how a CAT scan with contrast works and how to prepare for one.

What is contrast material?

Contrast material goes by many names: contrast dye, contrast media, contrast agent, and simply contrast. Regardless of which name you use, this material changes the way X-rays interact with your body. Because this material alters how the X-ray works, it helps “contrast” certain areas in your body. For example, if you need your blood vessels examined, the contrast agent helps to distinguish and highlight your blood vessels from other soft tissues. 

How does a CAT scan with contrast work?

Now let’s take a look at how CAT scans work: 

Receive the contrast material

Despite being called contrast dye, the material doesn’t dye (color) your organs. There are many types of contrast materials including iodine-based and barium-sulfate compounds, and they may be administered orally or intravenously. 

Depending on which type of contrast you need and what area of your body is being examined, our team recommends the right type of contrast for your needs. You may feel a metallic taste in your mouth, but if you receive it intravenously, you may notice a warm flushing sensation when you receive the contrast. Both of these reactions are normal and temporary.

The contrast material blocks the X-rays

Once you’ve received the dye, it goes to work! The contrast agent blocks the X-rays radiation. Because the contrast blocks the X-rays, it appears white on the CAT images. This helps emphasize your organs, blood vessels, intestines, or other structures being studied.

When you might need a CAT scan with contrast

There are many reasons why a CAT scan with contrast may be included into your treatment plan. CAT scan with contrast helps diagnose and evaluate conditions such as:

• Liver and kidney masses
• Blood perfusion in organs
• Thrombosis
• Inflammatory activity in inflammatory bowel disease

In addition to diagnosing and monitoring conditions, CAT scans with contrast can also be used to assess how well chemotherapy treatments are working.

Getting ready for your procedure

Regardless of why you need a CAT scan with contrast, you’ll need to follow specific instructions. You may be asked to limit food and drink prior to your test. Our team provides you with your detailed instructions, but if questions arise, don’t hesitate to give us a call. Feel free to call us if you have any questions.

You can reach our Houston, Texas, office at 713-300-4886, or you can simply schedule an appointment online.