CT Scan of the Brain and Spine

A CT scan is fast, widely available and excellent at showing bone. Dr. Grunch often uses it alongside an MRI, especially when she needs a close look at the bones of the spine, a fracture or a spinal fusion.

CT stands for computed tomography, sometimes called a CAT scan. It uses X-rays taken from many angles, which a computer turns into detailed cross-section pictures. You lie on a table that moves through a short, open ring. It is much more open than an MRI machine.

A CT scan is the best test for bone. It shows:

• Spine and skull fractures, such as burst fractures and skull fractures
• Bone spurs and arthritis that narrow the spaces for nerves, such as foraminal stenosis
• OPLL, a ligament that has turned to bone
• Whether a spinal fusion has healed, and the position of screws and rods
• Bleeding in the brain after a head injury, such as a subdural hematoma or epidural hematoma
• Hydrocephalus and shunt problems

Dr. Grunch also uses CT to plan surgery, because it shows the exact size and shape of the bones where screws or implants will go. A CT is the first test in the emergency room after a head or spine injury because it is so fast.

• A CT without contrast needs no special preparation. Eat and take your medicines as usual.
• Remove jewelry, glasses, hairpins and anything metal near the area being scanned.
• Tell them if you might be pregnant.
• If your CT uses iodine contrast dye, tell the center about any prior reaction to contrast, kidney disease, or if you take metformin for diabetes. You may be asked not to eat for a few hours beforehand.

You lie still on the table while it moves slowly through the ring. The scan itself takes only a few minutes, and the whole visit is often under 30 minutes. If contrast is used, it is given through an IV and may cause a warm, flushed feeling or a metallic taste for a moment.

You can drive and return to normal activities right away. If you had contrast, drink extra water for the rest of the day unless told otherwise. A radiologist reads the scan, and Dr. Grunch or one of her physician assistants will review the images with you.

CT uses a small amount of radiation. For the brain and spine, the dose is low and the benefit of getting the right diagnosis is much greater than the risk. Imaging centers use the lowest dose that gives clear pictures. CT is generally avoided during pregnancy unless it is truly needed.

What is the difference between a CT scan and an MRI?

CT uses X-rays and is best for bone, fractures and hardware. MRI uses a magnet and is best for discs, nerves, the spinal cord and the brain. Dr. Grunch often uses both to get the full picture.

Is a CT scan claustrophobic?

Usually not. The CT machine is a short, open ring rather than a long tube, and the scan takes only a few minutes.

How much radiation is in a CT scan?

A CT exposes you to more radiation than a plain X-ray but still a small amount. Imaging centers adjust the dose to the lowest level that gives clear pictures.

Why would Dr. Grunch order a CT after my fusion?

A CT is the best way to see whether the bones have fused together and whether the screws and rods are in good position.

If Dr. Grunch has ordered a CT scan for you and you have questions, call 470-293-9800 or contact us. You can also ask general questions any time through our “Ask Us Anything” chat. For questions about scheduling, cost or arrival time for the test itself, call the imaging center where it is booked.

Related: All imaging and diagnostic tests · Burst fractures · Revision fusion

This information is for educational purposes only and is not medical advice. It does not replace individualized care from a licensed physician. Please talk to your provider about your symptoms and follow the instructions from your imaging center.