Diagnosing Chiari Malformation

Medical imaging is used to diagnose Chiari Malformation. Traditionally the cerebellar tonsils had to herniate at least 5mm or more below the foramen magnum (base of skull). However, some doctors are considering smaller herniations. 
Chiari Malformaton MRI
CT of Chiari Malformation
- Magnetic Resonance Imaging 
   MRI's use magnets and radio waves to create detailed images. This is a safe and 
   painless test. It shows detailed images of the brain and other parts of the body. 
   Allowing the radiologist to assess where the cerebellar tonsils lie.
   The best view when getting diagnosed is a brain MRI (as seen on the right), an image 
   the craniocervical junction can also allow for a good view of the cerebellum. 
    MRI's machines can have different strengths which impact their quality, these appear like  2T or 3T on their advertising. With the higher number denoting a stronger magnet and better quality. To learn more about MRI's go to our MRI page
  A specialised imaging they can do is called a CINE MRI. This will show how the CSF is           flowing and show any areas of blockage. This can be helpful when surgeons are   questioning performing surgery. It is NOT always required as some cases show obvious   blockage in static images. 

Sometimes Chiari can be diagnosed via Computerized Tomography (CT), but a negative test does not rule out Chiari. 
- Computerized Tomography
  CT's uses x-ray scans to obtain cross-sections of the body. CT's expose the patient 
  to radiation. So are used sparingly. As MRI's show a much clearer image when 
  assessing Chiari it is preferred over CT's. 
CT of Craniocervical Junction
MRI of Brain
The most accurate way to diagnose Chiari Malformation is via Magnetic Resonance Imaging (MRI). 
Other tests/information your doctors may require include:
- Medical History
- Physical Exam
- Neurological Examination
These are used to assess if/how the chiari malformation is impacting the body.