Modalities

 

MRI & MRA | CT Scans | PET Fusion CT Scans | Mammograms | Ultrasound | X-Rays

 

Computed Tomography (CT) Scan:

 

How does a CT scanner work?

 

A CT scanner works much like an x-ray. The body casts a “shadow” on film when it is exposed to the x-ray, much like when you hold a flashlight up to your hand and cast a shadow on a wall. All of the tissue that the x-ray passes through overlap on the image, making it hard to isolate different elements. A CT scan works around this limitation of capturing only one very narrow “slice” of your body at a time. These “slices” can be viewed two-dimensionally or added back together to create a three-dimensional image of an organ or body structure.

 

The CT scanner moves around the patient on a circular gantry passing x-ray beams and taking thousands of pictures as it rotates.

 

CT can also be used to view arteries and veins, called Computed Tomography Angiography (CTA). The CTA uses a contrast dye (iodine) injected into the patient’s artery to help the computer “highlight” the arteries and veins.

 

What does a CT scan show?

 

CT scans are very good at showing bone, soft tissue, and blood vessels. While an MRI takes excellent pictures of soft tissue or blood vessels, a CT scan shows bone with higher definition, so it’s often used to image the spine or skull. It’s also used to view the inner ear and sinuses because these areas are made up of soft tissue and very fine bones.

 

Other detailed cross-sections can be taken of the brain, vessels of the brain, neck, shoulders, spine, discs, spinal cord, and vessels of the spine.

 

A CT scan can help your doctor diagnose many conditions including:

 

• Brain damage in people who’ve had a head injury.
• Brain tumors.
• Ruptured or leaking aneurysms.
• Hydrocephalus, or enlarged brain cavities.
• Spinal stenosis, or narrowing of the spinal canal.
• Herniated discs.
• Blood clots or bleeding associated with stroke.

 

Why is contrast agent used?

 

A contrast agent is an iodine liquid that makes certain organs and tissues stand out on the CT image. If you are receiving a contrast agent, it will be given through an injection or IV line before or during the exam. The contrast agent is a substance that x-rays cannot pass through. It circulates through your blood stream and can be x-rayed as it passes through the neck, brain or spine.

 

Who performs the test?

 

A radiology technologist will perform the test in the CT suite of the Radiology department of our outpatient imaging center. The radiologist will review the images and report their findings.

How should I prepare for the test?

 

You should wear loose clothing and remove all objects that would get in the way of the scan, such as hairpins, jewelry, etc. You may need to change into a gown provided in our center, depending on what part of your body is being Imaged. Be sure to tell your doctor if you’ve ever had an allergic reaction to iodine contrast or to any shell-fish.

 

What happens during the test?

 

You will be asked to lie on your back on a moveable table. If your head is being imaged, the technologist may position your head in a special holder that keeps it from moving. When you are comfortably positioned, the table will move into the CT machine that looks like a large donut with a round hole in the middle. You’ll be able to keep in contact with the technologist over an intercom. While each picture is being taken, you may be asked to hold your breath and stay perfectly still for a few seconds. The technologist will move your table with a remote control after each picture is taken.

 

What are the risks?

 

A CT Scan is a very safe study, though there is a slight risk from X-Ray radiation exposure, and some people are sensitive to the contrast agent. The most common side effects from the iodine contrast are a brief metallic taste in your mouth and a feeling of warmth throughout your body.

 

An extremely rare reaction occurs when you experience severe hives and have difficulty breathing. Medications such as antihistamines can reverse this reaction. If you have diabetes or kidney problems, it is very important that you make our staff aware of these concerns. Our staff is highly trained in the procedures to ensure your safety.

 

Be sure to tell our staff if you are pregnant or have a history of allergies, diabetes, asthma, a heart condition, kidney problems, sleep apnea, or thyroid conditions.

 

How do I get results?

 

The radiologist will promptly review your images and communicate directly with your referring doctor, who in turn will discuss the results with you. The estimated turn-around time for reports to be distributed to your physician, is 24 hours. This is typical timing unless your doctor has requested a Stat exam, in which the Radiologist will rush your dictation to the treating physician.