MRI-induced vertigo is a temporary feeling of spinning or dizziness experienced during a Magnetic Resonance Imaging scan. This sensation is a known side effect resulting from the powerful magnetic environment. While disorienting, it is considered harmless and is a direct biological response to the static magnetic field. Most individuals complete their imaging procedure without issue.
The Vestibular System and MRI Scanners
The mechanical cause of vertigo lies within the inner ear’s vestibular system, which controls balance and spatial orientation. Inside the semicircular canals is endolymph fluid, containing naturally occurring ionic currents, primarily potassium ions. The strong, static magnetic field interacts with these moving ions.
This interaction generates the Lorentz force, a physical force exerted on charged particles moving through a magnetic field. The force subtly displaces the endolymph fluid, pushing on the cupula, which houses the sensory hair cells. This deflection stimulates the vestibular nerve, tricking the brain into perceiving movement when the body is stationary. This artificial stimulation leads to vertigo and involuntary eye movements called nystagmus.
Expected Duration of MRI-Induced Vertigo
MRI-induced vertigo is very short, with the most intense spinning occurring as the patient moves into or out of the scanner. Magnetic field strength directly influences the likelihood and severity of the effect. Symptoms are far more common at ultra-high-field scanners (7 Tesla) than at 1.5T or 3T machines. At common field strengths, the incidence of vertigo is low, affecting less than 3% of patients.
For most people, the sensation of rotation diminishes rapidly, often within minutes of the head being positioned deep within the uniform magnetic field. Once removed from the strong magnetic field, the aftereffect—a transient sensation of spinning in the opposite direction—fades away quickly. This resolution is due to the brain’s rapid adaptation to the sudden absence of the stimulus.
Immediate Steps for Managing Dizziness
If you feel dizzy or experience spinning during the scan, immediately inform the technician using the call button or intercom. Remaining still minimizes the effect, as movement increases the force exerted on the inner ear fluid. Remembering the sensation is harmless and temporary helps manage anxiety that might worsen the dizziness.
After the scan, take your time getting up from the table. Sitting up slowly and allowing a few minutes to reorient yourself before standing is an effective strategy. Wait until the dizziness has fully subsided before attempting to walk unassisted or drive yourself home. If you feel faint or unsteady, tell the technologist, who will ensure you are stable before leaving.
When Vertigo Requires Medical Follow-Up
While MRI-induced vertigo resolves quickly, persistent or severe dizziness following the procedure warrants medical evaluation. If spinning lasts for hours or days, it is unlikely to be solely caused by the magnetic field and may indicate an unrelated underlying vestibular issue. Contact your healthcare provider immediately if the vertigo is accompanied by other neurological symptoms.
These red flags include a new or severe headache, changes in hearing, double or lost vision, difficulty speaking, or weakness in an arm or leg. These symptoms suggest a more serious, though rare, condition that requires immediate diagnosis and treatment. Seeking medical attention ensures that persistent balance problems are not mistakenly attributed to the MRI when a separate medical issue is present.