- Lets begin from the basics and go on to the main stuff ....
*At birth, the central nervous system does not contain any iron in it.
*As the child grows into an adult there is (physiologically normal) gradual deposition of iron in the central nervous system.
*The part of the central nervous system where this iron deposition is most significant is the globus pallidus.
*Given below is an axial MRI image (T1 weighted) of the brain showing the exact location of the globus pallidus.
*The exact image of the tiger eye sign cannot be posted here due to copyright issues, but you can see the image here ----> click here
*At birth, the central nervous system does not contain any iron in it.
*As the child grows into an adult there is (physiologically normal) gradual deposition of iron in the central nervous system.
*The part of the central nervous system where this iron deposition is most significant is the globus pallidus.
*Given below is an axial MRI image (T1 weighted) of the brain showing the exact location of the globus pallidus.
*Now this excessive iron deposition in the globus pallidus bilaterally with a central area of gliosis and edema changes gives the appearance of tigers eyes because of the different shape of globus pallidus.
*The peripheral iron appears hypointense (black on MRI) and the central gliosis and edema changes appear hyperintense (white on MRI) giving the appearance described above.
*One of the conditions in which this occurs is Hallervorden-Spatz syndrome.
*The exact image of the tiger eye sign cannot be posted here due to copyright issues, but you can see the image here ----> click here
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