| Subject | Contents |
| Definition | A CT scan (computed tomography) of the orbits (the eye sockets) and the globes (the eyes). |
| Alternative Names | CT scan - orbital
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| How the test is performed | A contrast dye may be injected into a vein before the test. You lie on the table (gantry) which can be moved by the technician operating the scanner. Only the head is positioned inside the CT scanner. The head may be positioned on a pillow or otherwise made more comfortable before the test, but this must be done before the scan begins. The exam should last no more than a few minutes. |
| How to prepare for the test | You must sign an informed consent form. Remove your dentures, jewelry and other metals. 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) schoolage 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. |
| Normal Values | |
| What abnormal results mean | Graves' disease lesion(s) tumor hemorrhage |
| What the risks are | The amount of radiation in a CT scan is minimal; however, there may be some concern for nursing or pregnant women because fetuses and breast-fed infants are more susceptible to the effects of radiation directed upon the mother. Most often, the benefits of the scan outweigh the risk to the fetus. |
| Special considerations | The contrast dye may cause adverse reactions in some patients. These reactions may include headache , nausea , and vomiting . |
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