A cranial CT scan is computed tomography of the head, including the skull, brain, orbits (eye sockets), and sinuses.

A head CT will produce an image from the upper neck to the top of the head. It is important that once your head is in place, you do not move it during the test; if you are unable to keep your head still, immobilization may be needed. All jewelry, glasses, dentures, and other metal should be removed from the head and neck to prevent obstruction of the images.

A contrast dye may be injected into a vein to further check a mass. The mass becomes brighter with contrast dye if it has a lot of blood vessels. Contrast dye is also used to produce an image of the blood vessels of the head and brain.

The total amount of time in the CT scanner is usually a few minutes.

Generally, there is no preparation necessary.

The contrast dye injection may cause a slight temporary burning sensation in the arm, metallic taste in the mouth, or whole body warmth. This is a normal occurrence and will disappear in a few seconds.

Otherwise, the CT scan is painless.