What is the process for obtaining approval for a computed tomography (CT) scan to evaluate vertigo (dizziness)?

From the Guidelines

To get a CT scan approved for dizziness, you should first consult with your primary care physician who will evaluate your symptoms and medical history, and if your dizziness is severe, persistent, or accompanied by other neurological symptoms, your doctor may determine that a CT scan is medically necessary, as supported by the American College of Radiology Appropriateness Criteria 1.

Key Considerations

• The diagnostic yield of CT scans for dizziness is generally low, with a positivity rate of approximately 2% in the emergency department setting 1.
• Patients with isolated dizziness, without vertigo, ataxia, or other neurologic deficits, have a very low probability of detecting an abnormality on CT or MRI, with a diagnostic yield of less than 1% for CT and 4% for MRI DWI 1.
• The HINTS examination, when performed by specially trained practitioners, can be used to distinguish acute vestibular syndrome (AVS) of benign cause from posterior circulation infarct, and may reduce the need for imaging in some cases 1.

Steps to Get a CT Scan Approved

• Consult with your primary care physician to evaluate your symptoms and medical history.
• Undergo a physical examination and initial tests, such as blood work or a basic vestibular examination.
• If your dizziness is severe, persistent, or accompanied by other neurological symptoms, your doctor may determine that a CT scan is medically necessary.
• Be prepared to describe your dizziness in detail, including duration, triggers, associated symptoms, and how it affects your daily activities.
• Your doctor may need to submit a prior authorization request to your insurance company with specific medical justification for the imaging study, as the use of CT imaging for dizziness has increased over the past several decades, but the detection rate of contributory central nervous system pathology remains low 1.

From the Research

Getting a CT Scan Approved for Dizziness

To get a CT scan approved for dizziness, consider the following points:

• The decision to approve a CT scan for dizziness is typically based on the patient's symptoms, medical history, and the results of a physical examination 2, 3, 4.
• Studies have shown that the diagnostic yield of head CT scans for acute dizziness is low, ranging from 1.6% to 2.2% 3, 4.
• However, in certain cases, such as when there is a suspicion of a central cause of dizziness, a head CT scan may be ordered to exclude other conditions 3.
• The American College of Radiology appropriateness criteria suggest that MRI may be a more useful diagnostic tool for evaluating dizziness, particularly in cases where the cause is unclear 3.
• A clinical suspicion based on the patient's anamnesis and exploration is recommended to make a good selection of tests to request, including CT scans or MRI 2.

Factors Influencing CT Scan Approval

Some factors that may influence the approval of a CT scan for dizziness include:

• Patient demographics, such as age and sex 4
• Presence of other symptoms, such as depression or frequent emergency department visits 2
• Frequency and severity of dizziness episodes 4
• Results of previous diagnostic tests, such as MRI or other imaging studies 3, 4

Alternative Diagnostic Tools

In some cases, alternative diagnostic tools, such as MRI, may be more effective in evaluating dizziness, particularly in cases where the cause is unclear 3, 4.

• MRI has been shown to change the diagnosis in up to 16% of cases, and may be a more useful tool for evaluating dizziness in certain patient populations 3.