A CT of the temporal bone is a specialized, high-resolution scan that focuses on the temporal bones, which are located at the sides and base of your skull. These bones house the delicate structures of your ears, including the middle ear, the inner ear, the hearing canal, and the master balance centers.
If you experience unexplained hearing loss, persistent ear discharge, or chronic infections, this scan provides highly detailed, thin-slice images of the bone and tiny ear structures.
Common Indications for a CT of the Temporal Bone
- Evaluating chronic middle ear infections or cholesteatoma (a non-cancerous skin growth).
- Investigating unexplained conductive or sensorineural hearing loss.
- Evaluating trauma or fractures to the side of the skull.
- Investigating persistent dizziness or balance disorders (vertigo).
- Pre-operative planning before cochlear implant surgery.
- Checking for congenital ear abnormalities in children.
What exactly does a CT of the temporal bone show?
The scan shows high-resolution, cross-sectional views of the middle ear cavity, the ear ossicles (three tiny hearing bones), the inner ear canals (cochlea and semicircular canals), and the mastoid air cells (air spaces behind the ear).
How should I prepare for a CT of the temporal bone?
Fasting is not usually required for a standard noncontrast scan unless sedation or another procedure is planned. Follow the centre's instructions and remove metal items from the head and neck when asked because they can distort the images.
Do I need to stop taking medication?
Do not stop prescribed medication unless the clinical team tells you to. Ask in advance if sedation, contrast, or another procedure is planned.
What happens when I arrive for my scan?
You will lie down on the scanner table in the CT room. The radiographer will help position your head in a specialized head cradle and may use a soft strap to help you keep your head completely still during the scan.
How is the procedure performed?
You will lie flat on your back. The scanner table will slide slowly into the doughnut-shaped CT scanner. The scanner will rotate around your head, making a whirring or humming sound. You must remain completely still, as even minor movements can blur the tiny structures of the ear. The radiographer will monitor you from the control room.
How long does a CT of the temporal bone take?
The actual scanning takes less than 30 seconds. The entire appointment takes about 10 to 15 minutes.
Is there any discomfort?
The scan itself does not usually hurt, although keeping still or lying with an existing injury may be uncomfortable.
Are there risks?
Yes. The scan uses X-rays, but the radiation dose is kept to the lowest possible level. The benefit of diagnosing ear and hearing conditions outweighs the small radiation risk.
Can children have this scan?
Children may have this scan when it is clinically justified. The field and exposure should be adjusted to the child's size and the diagnostic task, and MRI or another lower-radiation test should be considered when it can answer the question.
Can I have this scan if I am pregnant?
Pregnancy Precaution
Tell the clinician and CT team if you are pregnant or could be pregnant. The pelvis is outside the beam, so fetal exposure from a correctly performed temporal-bone CT is expected to be very low. The team should still justify the scan and use an optimised protocol.
When will I get my results?
A radiologist will review the images and send a report to the referring clinician. Timing varies by urgency and facility, so ask when and how the result will be provided.
What if the scan finds something?
If the scan identifies an infection, fluid, or bone damage, your ENT doctor will discuss treatment. This may involve specific medications, ear drops, or ear surgery (such as mastoidectomy) to clean out chronic infections.
Questions to ask your team
- Is the scan assessing hearing loss, infection, trauma, cholesteatoma, or surgical anatomy?
- Will it be a focused high-resolution, usually noncontrast protocol?
- Would MRI be needed for nerves, inner-ear soft tissues, or a suspected mass?
Sources and further reading
Conclusion
A CT of the temporal bone is a highly precise tool for evaluating ear and hearing issues. To ensure a clear scan, remember to remove all metal items from your ears and neck and lie completely still.