| Subject | Contents |
| Definition | A CT scan (computed tomography) of the head, including the skull, brain, orbits (eyes), and sinuses. |
| Alternative Names | Head CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses
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| How the test is performed | A head CT will image from the upper neck to the top of the head. If the patient cannot keep his/her head still, immobilization may be necessary. All jewelry, glasses, dentures, and other metal should be removed from the head and neck to prevent artifact. Intravenous contrast media may be administered to further evaluate for vascular masses, determine whether masses enhance (become brighter) with contrast, or allow for visualization of the vessels of the head and/or brain. The total amount of time in the CT scanner should be a few minutes. |
| How to prepare for the test | There is no preparation necessary. 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 | As with any intravenous iodinated contrast injection, there may be a slight temporary burning sensation in the arm, metallic taste in the mouth, or whole body warmth. This is a normal occurrence and will subside in a few seconds. Otherwise, the CT is painless. |
| Why the test is performed | A CT scan is recommended to help:
evaluate acute cranial-facial trauma determine acute stroke evaluate suspected subarachnoid or intracranial hemorrhage evaluate headache evaluate loss of sensory or motor function determine if there abnormal development of the head and neck
CT scans are also used to view the facial bones, jaw, and sinus cavities.
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| Normal Values | |
| What abnormal results mean | There may be signs of: trauma bleeding (for example, chronic subdural hematoma , subarachnoid or intracranial hemorrhage )stroke masses or tumors abnormal sinus drainage sensorineural hearing loss malformed bone or other tissues brain abscesscerebral atrophy (loss of brain tissue) cerebral edema (brain tissue swelling )hydrocephalus (fluid collecting in the skull) Additional conditions under which the test may be performed:acoustic neuromaacoustic traumaacromegalyacute (subacute) subdural hematomaamyotrophic lateral sclerosisarteriovenous malformation (cerebral)benign positional vertigocancer of the throat central pontine myelinolysiscerebral aneurysmCushing's syndromedeep intracerebral hemorrhagedeliriumdementiadementia due to metabolic causesdrug-induced tremorencephalitisepilepsyessential tremorextradural hemorrhagefamilial tremorgeneral paresisgeneralized tonic-clonic seizurehemorrhagic strokehepatic encephalopathyHuntington's diseasehypertensive intracerebral hemorrhagehypopituitarismintracerebral hemorrhagejuvenile angiofibromalabyrinthitislobar intracerebral hemorrhageLudwig's anginamastoiditismelanoma of the eyeMeniere's diseasemeningitismetastatic brain tumormulti-infarct dementiamultiple endocrine neoplasia (MEN) Ineurosyphilisnormal pressure hydrocephalus (NPH)occupational hearing lossoptic gliomaorbital cellulitisotitis media; chronicotosclerosispartial (focal) seizure partial complex seizure petit mal seizurepituitary tumorprimary brain tumorprimary lymphoma of the brainprolactinomaretinoblastomaReye's syndromeschizophreniasenile dementia/Alzheimer's typeacute sinusitisstroke secondary to atherosclerosisstroke secondary to cardiogenic embolismstroke secondary to FMDstroke secondary to syphilissubarachnoid hemorrhagesyphilitic aseptic meningitistemporal lobe seizuretoxoplasmosistransient ischemic attack (TIA)Wilson's disease |
| What the risks are | Iodine is the usual contrast media (dye). Some patients are allergic to iodine and may experience a reaction that may include hives , itching , nausea , breathing difficulty , or other symptoms. As with any X-ray examination, radiation is potentially harmful. Consult your health care provider about the risks if multiple CT scans are needed over a period of time. |
| Special considerations | A CT scan can decrease or eliminate the need for invasive procedures to diagnose problems in the skull. This is one of the safest means of studying the head and neck. |
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