Magnetic resonance imaging (MRI)

What it is

Magnetic resonance imaging (MRI) is the main, gold-standard imaging test for diagnosing Chiari malformation. Using powerful magnets and radio waves (not radiation), it produces detailed images of the brain, spinal cord, and the craniocervical junction.

Understanding Magnetic resonance imaging (MRI)

MRI clearly shows the soft tissues involved in Chiari — the cerebellar tonsils and their position relative to the foramen magnum, the brainstem, the spinal cord, and any syrinx. It is used to confirm the diagnosis, measure the degree of tonsillar descent, determine the type, detect associated findings (such as a syrinx, hydrocephalus, or bony abnormalities), and plan treatment. MRI of the brain is typically combined with imaging of the cervical (and often the whole) spine, since a syrinx can occur anywhere in the cord. Because MRI does not use radiation, it is well suited for diagnosis and for follow-up monitoring. MRI is central to essentially every stage of evaluating Chiari. Understanding MRI clarifies the primary test that makes diagnosis and planning possible.

Why it matters

Understanding MRI helps families see that this detailed, radiation-free test is central to diagnosing Chiari, classifying it, detecting a syrinx and other findings, and planning treatment and follow-up.