CT scan - orbital

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Alternative names
Orbit CT scan

Definition
An orbital CT scan is a procedure that uses computed tomography to examine the orbits (the eye sockets) and the globes (the eyes).

How the test is performed

A contrast dye may be injected into a vein before the test.

You lie on a table that can be moved by the technician operating the scanner. Only your head is positioned inside the CT scanner. The exam usually lasts no more than a few minutes.

You may be allowed to rest your head on a pillow, but this must be done before the scan begins.

How to prepare for the test

You must sign an informed consent form. Remove dentures, any jewelry, and anything metal.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child’s age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child’s age:

• Infant test or procedure preparation (birth to 1 year)
  
• Toddler test or procedure preparation (1 to 3 years)
  
• Preschooler test or procedure preparation (3 to 6 years)
  
• School age test or procedure preparation (6 to 12 years)
  
• Adolescent test or procedure preparation (12 to 18 years)

How the test will feel
The most discomfort arises from the need to lie still on the table during the scan. The scan itself is painless.

Why the test is performed
This test is helpful in diagnosing a lesion or other disease which affects the tissues around the eyes, sinuses, optic nerves (nerves supplying the eyes), or eye muscles and vessels. As well, subtle fractures of the orbits can be detected.

What abnormal results mean

• Graves’ disease
  
• Lesions
  
• Tumor
  
• Hemorrhage

What the risks are
The amount of radiation in a CT scan is minimal. There may be some concern for nursing or pregnant women. However, the benefits of the scan generally outweigh any risk to the fetus or newborn.

Special considerations
The contrast dye may cause adverse reactions in some patients. These reactions may include headache, nausea, and vomiting.

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