Neurosurgery Radiology

  1. General Concepts
    • Scan intervals – 10mm in adults, 7mm in children, 5mm in infants
    • Base line in orbito-meatal line in CT scan.
    • In MRI, there is no angle, we start from base of skull (foramen magnum) and go upwards.
  2. MRI Protocals
    • - Axial T1 – fluid is black. White mater is white, grey mater is grey
    • - Axial T2 – fluid is white [@ World War II - Water is White in T2] 
    • - Axial FLAIR – all same as T2 except fluid is black
    • - Saggital T1
  3. Infratentorial anatomy?
    • - Identify 4th ventricle. Anterior to 4th ventricle is brain stem. Posterior is cerebellum.
    • - 4th ventricle is large in middle. It becomes smaller while we go up and go down.
    • - The part of brain stem anterior to largest part of 4th ventricle is pons. Anterior to pons is the basilar artery. Basilar artery lies in prepontine cistern (retrosellar cistern – behind dorsum sellae). Posterior to it is cerebellar vermis. Posterior to cerebellar vermis is cisterna magna.
    • - Prepontine cistern has extension in the left and right side known as cerebello-pontine angle cisterns (ambient cistern)
    • - The junction between cerebellum and pons is cerebello-pontine cistern.
    • - Trigeminal nerve comes out from pons, and goes to cerebello-pontine angle cistern and reach the parasellar area
    • - When we go below the level, 4th ventricle becomes smaller and smaller. When 4th ventricle has become smaller inferiorly, the part of brain stem anteriorly is the medulla.
    • - Now, we can see the CSF space running inferiorly known as Vallecula.
    • - Cisterna magna lies posterior to cerebellum.

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  4. Infratentorial anatomy Contd?
    • - When we go above the level of 4th ventricle largest dilatation, the structure anterior to the 4th ventricle is the midbrain.
    • - Midbrain is surrounded from its posterior aspect by cistern called as quadrigeminal cistern. In the middle of the quadrigeminal cistern, we find the terminal part of 4th ventricle and start of aqueduct of Sylvius.
    • - At the level of mid brain, is the temporal horn of lateral ventricle. The structure between the temporal horn of lateral ventricle and the mid brain is known as hippocampal formation (hippocampus and amygdala).
    • - At the level of the midbrain are the cerebral peduncles and the interpeduncular cistern. In the interpeduncular cistern are the two small rounded structures called as mammilary bodies.
    • - Slightly anterior to the mammilliary bodies are the optic tract after coming from decussation above the sella.

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  5. Basal Ganglia Anatomy?
    • Caudate nucleus, particularly head,  lies in the concavity of frontal horn of lateral ventricle.
    • Lateral to caudate nucleus is the the lenitiform nucleus.
    • On either side of third ventricle is the thalamus.
    • Between the caudate, lentiform and thalamus is the internal capsule.


    The quadrigeminal cistern, higher up is seen as rhomboid shaped. It has 4 recessess.

    Inside the quadrigeminal cistern, there are 4 structures. The pineal body that usually calcifies in adults.  Two internal cerebellar veins  and the vein of Galen.

    • Lateral limbs of this cistern is retrothalamic cistern and posterior limb is called as superior cerebellar cistern. Posterior to the retrothalamic cistern is the tail of hippocampus.Calcification in the occipital horn of the lateral ventricle is the calcification of choroid plexus.
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  6. High ventricular anatomy?
    • Body of Lateral ventricles are separated by septum pellucidum.
    • In the concavity of lateral ventricle body, there is the relatively dense structure which represents the body and the tail of the caudate nucleus.
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  7. Lobar anatomy?
    If ventricles are seen, divide into 3 equal parts

    Anterior third is frontal, posterior lobe is occipital.

    If we see the third ventricle, we are in the inferior lobe, and hence the temporal lobe.If we see the body of ventricle, then the segment is superior, and hence the parietal lobe

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    If no ventricles are seen, divide into 4 equal parts

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    • If even higher up, then, there is only parietal lobe.
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  8. Major cisterns
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Author
prem77
ID
331019
Card Set
Neurosurgery Radiology
Description
Neurosurgery
Updated