Imaging

Computerized Tomography (CT or CAT scan) is an X-ray technique that allows us to see bones and organs with a high degree of precision. A conventional X-ray uses a stationary machine to focus beams of radiation on a specific part of your body, while a CT uses an X-ray generating device that rotates around your body and a powerful computer to create cross-sectional images (slices) of your body’s interior.

For Your Safety

Tell your doctor if you are pregnant or suspect you may be pregnant. Your doctor may postpone the exam or choose an alternative exam to reduce the possible risk of exposing your fetus to radiation.

Unlike an MRI, CT scans can be performed if you have a pacemaker.

Some CT exams require patients to consume a contrast material (either by mouth or IV) in order to create a better image. If you have allergies or asthma and your CT scan requires a contrast material, there is a slight risk of an allergic reaction to the material. Most reactions result in itchiness or hives. For individuals with asthma who are allergic, the reaction can be an asthma attack. In very rare instances, an allergic reaction may cause swelling in your throat or other areas of your body. Diabetes, heart disease, kidney problems or thyroid conditions also increase your risk of reaction to the contrast material. Immediately tell your technologist or doctor if you experience any of these symptoms during or after your exam. Our staff and physicians are prepared should any type of emergency situation occur.

CT scan risks are similar to those of conventional X-rays. You are briefly exposed to radiation during the CT scan. Scientific and medical experts believe that enough valuable information is provided to outweigh the associated risks.

Preparing for a CT Exam

Preparation for your CT scan depends on which part of your body will be scanned. Some scans, typically abdominal and pelvic, require a liquid contrast medium prior to your exam. Contrast medium can be taken by mouth, enema or intravenously. The oral contrast is used to visualize your intestinal tract, while an IV contrast helps to emphasize blood vessels. The contrast medium blocks X-rays and appears white on images, which helps emphasize the blood vessels.

If you are scheduled for a CT abdomen and/or pelvis, please arrive 1 hour and 30 minutes before appointment time for contrast prep.

You may eat a normal diet and take daily medications, however, depending on the body area being scanned, your doctor may ask you to temporarily modify your diet, take laxatives, enemas or suppositories.

For CT scans of the chest, abdomen and pelvis:

• You may take your usual medications with water, but do not eat anything for at least four hours before your test. You may have clear liquids for four hours prior.
• If you are on Glucophage (Metformin) you should take your morning dose, and you should see your doctor for a blood test before taking Glucophage again.

What to Expect During a CT Exam

CT scans are painless and can be expected to last no more than an hour depending on the required preparation and whether use of a contrast medium is included.

Prior to the exam, you may be asked to remove your clothing and put on a hospital gown. You will also be asked to remove all metal or electronic objects from your body before the exam as these objects interfere with the quality of the images. Our technologist will prepare and guide you by explaining the procedure, assisting in removal of jewelry and other metal objects and positioning you to ensure the highest quality images are obtained from your exam.

You may feel a brief sensation of heat or experience a metallic taste in your mouth if a contrast material is used. If an enema is used to administer contrast, typically for gastrointestinal exams, you may feel cramping or a sense of fullness.

You will lie on a narrow table that slides through the opening of a large device called the gantry. The table can be raised or lowered. During a CT scan, a special head cradle, pillows or straps may be used to help you remain in position.

The table will move slowly through the gantry as the X-ray tube rotates around your body. You may be asked to hold your breath while the table is moving to avoid blurring the images. You will hear noises similar to a small airplane or spinning clothes dryer as the X-ray rotates to create images of your body.

The technologist supervises the CT scan from a control room and can always see and hear you. An intercom is used to communicate. When your exam is complete you may leave and resume regular activities based on your doctor's instructions. If you received a contrast material you will be given instructions to help remove the material from your body. This will likely include drinking lots of fluids.

Results

A radiologist will review your exam images and report the findings to your doctor within 24 hours. Your doctor will then discuss the findings and next steps with you.