====== Hannover Grading Scale ======

Classification of Samii (Hannover System).

see Hannover grading scale.


Classification system of the [[vestibular schwannoma]]

{{::hannovergrading.png?400|}}

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T1, purely intrameatal

{{::hannover_grading_scalet1.jpg?200|}}

T2, intra-extrameatal

T3a, occupying the [[cerebellopontine angle cistern]]

{{::hannover_grading_scalet3a.jpg?200|}}

T3b, reaches the trunk of the brain ([[brainstem]]).

T4a, compresses the trunk of the brain

T4b, displaces the trunk and compresses the fourth ventricle.