Most of the time, doctors ordering a CT scan or MRI of your temporal bone – the bone enclosing your inner ear – are looking for major structural abnormalities. Usually, they want to see the health of the bone, whether or not it is intact, and if there are any tumours on the balance and hearing nerve or on the structures at the back of your head. An acoustic neuroma, for example, is a benign tumour causing hearing loss and dizziness as it grows around the hearing and balance nerve. Acoustic neuromas show up on an MRI.
Neither CT scans nor MRIs can, however, help diagnose most causes of dizziness and imbalance. Imaging cannot show if the tiny inner-ear balance sensors are working. In summary, the role of medical imaging is to rule out – or in – certain structural causes for balance and dizziness disorders.