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CT of the Internal Auditory Canals Without Contrast

Published: August 9, 2026Updated: August 16, 2026

A CT scan that creates detailed images of the internal auditory canals in the temporal bones without using IV contrast.

Quick summary

This scan evaluates the bony ear canals and nearby structures that may contribute to hearing loss, balance problems, or facial nerve symptoms.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30584-7
Short code
CT IAC WO contr
Synonyms
CT IAC WO contr
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This is a computed tomography scan of the internal auditory canals, the passages in the skull that carry the hearing and balance nerves from the inner ear to the brain. It is performed without injected contrast material.

Why might I need this test?

It may be ordered to evaluate unexplained hearing loss, tinnitus, dizziness, or facial nerve weakness. The scan can show fractures, narrowing, bone growth, or other structural changes affecting the inner ear and nearby tissues.

How is the test performed?

You will lie on a CT table while the scanner takes multiple X-ray images from different angles. The scan is generally painless and usually takes less than 30 minutes.

How do I prepare for the test?

No fasting or contrast-related preparation is usually required. Remove metal objects and tell the imaging team if you are pregnant, have recently received contrast, or experience claustrophobia; follow any instructions provided by the facility.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal findings may indicate a temporal bone or internal auditory canal fracture, bony narrowing, or another structural abnormality that can affect hearing or balance. Some findings may help explain symptoms such as vertigo, tinnitus, or facial weakness. Your clinician will interpret the scan together with your symptoms, examination, and other tests.

Short name

CT IAC without contrast

Frequently asked questions

Does this CT scan use contrast?
No. This study is performed without injected contrast material, so there is generally no need to wait afterward for contrast to pass through the kidneys.
Is the CT scan painful?
The scan itself is painless. You may be asked to remain very still, and the enclosed scanner can feel tight, particularly if you have claustrophobia.
What can the scan detect?
It can show bony changes, fractures, narrowing, and structural abnormalities around the inner ear and internal auditory canals. Some soft-tissue or nerve abnormalities are better evaluated with MRI, so additional testing may be recommended.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy