CT Scan

A CT scan involves a series of X-rays. Using a machine, we take the X-rays from different angles. A computer then puts the X-rays together to create cross-sectional images, or slices, of the area of your body being studied. We record the images on a computer and can print them out as photographs.

On a CT scan:

• Air-filled spaces, such as your sinus cavities, appear black
• Dense areas, such as bones, appear white
• Less dense areas, such as tissue or muscles appear as shades of gray
• Parts of your body filled with fluid, such as your brain’s ventricles, appear dark gray

We perform CT scans for many reasons. If you’re receiving emergency care at Anna Jaques, for example, CT scans are available 24/7. A brain scan may help us determine if you’re having a stroke. Or if you’ve been injured in an accident, a CT scan may identify internal bleeding or other injuries that help us provide quick, lifesaving care.

Other things a CT scan can help us diagnose include:

• Blood clots and blood flow problems
• Conditions affecting internal organs, such as your lungs, kidneys or liver
• Dental problems
• Noncancerous tumors and cysts
• Spinal conditions

Positron emission tomography in conjunction with CT scanning (PET/CT scan) helps us identify cellular changes in your body. It may lead to an earlier diagnosis of conditions such as cancer, heart disease or brain disorders.

Generally, no special preparation is needed for a CT scan. However, if you’re having a scheduled exam, you may be most comfortable wearing loose-fitting clothing. Depending on the area being studied, we may ask you to remove eyeglasses, hearing aids, piercings or other items that might interfere with imaging.

Sometimes, we use contrast material to enhance CT images. If you’re having a CT scan with contrast, we’ll ask you to avoid eating or drinking for a few hours before your test. We may give the contrast by injection or ask you to swallow it. Some people feel warm after the injection or experience an unpleasant taste in their mouth. They also may feel like they need to urinate. These feelings pass quickly.

It’s important to tell us about any recent illnesses you have had, as well as if you have a history of diabetes, kidney disease, heart disease, asthma or thyroid disease. If there’s any chance you might be pregnant, it’s important to mention that as well.

The test takes place on a table that moves into the X-ray machine. In most cases, you lie on your back.

The table will move quickly through the scanner the first time. Then it will move a bit more slowly as the scan takes place. Sometimes, more than one pass through the scanner is needed. We may ask you to hold your breath briefly. This improves the quality of the images.

Once the exam is complete, we may ask you to wait while we verify that the images are satisfactory.

One of our radiologists will interpret your scan and send a report to your doctor, who will get the results to you. They may be available through our patient portal. Overall, this process may take several days.