Neck (Cervical Spine) CT scan (with contrast)

What it is

CT builds cross-sectional images from X-rays, and it is very good at bone. That is why the great majority of cervical spine CT scans — after a car crash, a fall, or any injury where a broken neck has to be ruled out — are done with no dye at all. This code is the less common version, where an iodine-based contrast material is injected into a vein before the scan. Iodine circulates in the blood, so tissue with a rich blood supply becomes brighter than tissue without. That difference is the whole point: it is what separates an abscess from ordinary swelling, or shows the edge of a mass against the muscle next to it. The vertebrae themselves look much the same either way.

Why it is done

• To look for an infection in or around the spine, such as a collection of pus that needs draining
• To outline a mass in the neck and show how it relates to the vertebrae and the surrounding structures
• To follow a known tumor in the neck, where the question is whether it has grown or spread
• To assess soft tissue after previous surgery or radiation to the neck
• To evaluate the neck when MRI cannot be used — for example because of an implanted device that is not MRI-safe

What to expect

The scan itself is quick; the preparation around it is what takes time. An intravenous line is placed, usually in the arm. Because contrast may be given, patients are typically asked not to eat for a period beforehand, and are asked about allergies and about kidney function, since iodine contrast is cleared by the kidneys. When the dye goes in, a spreading feeling of warmth and a metallic taste are common and pass within a minute. The actual imaging takes seconds to a couple of minutes while the table moves through the scanner ring. There is radiation exposure, unlike with MRI or ultrasound. A radiologist reads the study and reports to the ordering doctor.

Questions worth asking

• Is the contrast actually needed for the question being asked? A cervical spine CT without contrast is a separate, generally cheaper code, and for bone questions it is the usual choice.
• Will the contrast material itself appear as its own line on the bill, over and above the scan charge?
• Is an MRI of the neck being considered as well? Ordering both in the same week means paying for both, and the two answer different questions.
• If this is being done in an emergency department, ask whether an emergency facility fee is attached that an outpatient radiology appointment would not carry.