Central nervous system

Guanghui YuRadiology college

Brain

Spinal cord

Central nervous system

Radiographic technique

technique brainSpinal

cord

Image acquisition time

application

Plain film

invisible invisible elimination

CT visible invisible fastEmergency

radiology

MRI visible visible low others

DSA vesselsvascular diseases

Grey and white matter

Neural tissue

Axon (surrounded by myelin)

Cell body (more H2O)

Fatty substance (white in color)

white matter

Grey matter

CT MR T1WI T2WI

white matter hypodense high low

Grey matter hyperdense low high

white matterGrey matter

hyperdense hypodense

T1WI T2WI

hypointensityhyperintensity

(Grey matter)(white matter)

hypointensity

hyperintensity

T1WI FLAIR T2WI

Fluid attenuated inverse recovery

The brain consists of

a 、 the brain stem b 、 the cerebellum c 、 the forebrain

pons

midbrain

medulla oblongata

cerebellum

Spinal cordcerebellar tonil

the forebrain

frontal lobe

parietal lobe

temporal lobe

occipital lobe

insular lobe

Corona radiata

Genu of Corpus callosum

Head of caudate nucleus

Lentiform nucleus

Splenium of Corpus callosum

Thalamus

Internal capsule

External capsule

Basal ganglia

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A midline Post-contrast Sagittal T1 Weighted MRI

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1. Scalp fat2. Bone3. Inferior sagittal sinus4. Corpus callosum5. Internal cerebral vein6. Vein of Galen7. Superior sagittal sinus8. Parietal lobe9. Occipital lobe10. Straight sinus11. Vermis12. IV ventricle13. Cerebellar tonsil14. Cervical cord15. Medulla16. Pons17. Midbrain18. Mass intermedia of thalamus19. Anterior III ventricle 20. Optic chiasm21. Pituitary gland22. Sphenoid sinus23. Nasopharynx24. Frontal lobe

Coronal Section of the Brain at the level of IV VentriclePost Contrast Coronal T1 Weighted MRI

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11. Cerebellar tonsil2. Cerebellar hemisphere3. IV ventricle4. Superior vermis5. Tentorium6. Posterior temporal lobe7. Choroid plexus within lateral ventricle8. Posterior frontal lobe

Meninges

dura mater the outer layer arachnoid mater the middle layer pia mater the inner layer inseparable from the brain

The cranial dura is formly adherent to the periosteum of skull bones

The arachnoid mater is loosely adherent to the dura mater Between the arachnoid and the pia is the subarachnoid space

A double layer of dura projects into the cranial cavity.

These dural folds form:

Falx cerebri

Tentorium cerebelli

Diaphragm of sella turcica

meninges:

arachnoid

pia mater

dura

Falx cerebri

Tentorium cerebelli

Diaphragm of sella turcica

Subarachnoid space

cerebral falx

cerebral falx

Tentorium cerebelli

ventricular system and cerebrospinal fluid

Lateral ventricle

Anterior horn of lateral ventricle

Interventriculer foramenForamen of Monroe

Cerebral aqueduct

Fouth ventricle

third ventricle

posterior horn of lateral ventricleinferior horn of lateral ventricle posterior horn of lateral ventricle

inferior horn of lateral ventricle

pineal body

Cerebrospinal fluid circulation and cistern

Cerebrospinal fluid

Produced by the choroid plexus in all ventricles

the lateral ventricle the third ventricle

Foramen of Monro

the fouth ventricle

cerebral aqueduct

Subarachnoid space

Superior sagittal sinusarachnoid granulation

Median and lateral aperture of fourth ventricle

cistern ： At several sites where the surface of the brain is deeply fissured, the subarachnoid space is wider than at other sites.

bilateral ： interhemispheric cistern cistern of lateral sulcus cisterna ambiens cistern of pedunculus cerebellaris pontinus

Post Contrast Axial MR Image of the brain

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Post Contrast sagittal T1 Wtd M.R.I.

Section at the level of Pons

Answers

8. Cerebellar Hemisphere

9. Vermis

10. IV Ventricle

11. Pons

12. Basilar Artery

13. Internal Carotid Artery

14. Cavernous Sinus

15. Middle Cerebellar Peduncle

16. Internal Auditory Canal

17. Temporal Lobe

acoustic nerve

facial nerve

unilateral ：

dorsal

cisterna venae magnae cerebri

quadrigeminal cistern

ventral

cistern of chiasma

interpeduncular cistern

suprasellar cistern

consecutive

suprasellar cistern

hexagon

chiasma

Cerebral peduncle

interpeduncular cistern

suprasellar cistern

Vertebralartery

basilar artery

basilar artery posterior cerebral artery

middle cerebral artery

anterior cerebral artery

posterior communicating artery

internal carotid artery

cranial sinuses

Pituitary gland

anterior pituitary adenohypophysis

posterior pituitary neurohypophysis

Pituitary gland

• MR thin slice scan Coronal and sagittal scan

• Height:<7millimeter

• superior margin: flat or depressed

• Pituitary stalk:<4millimeter

Coronal Section of the Brain at the level of Pituitary glandPost Contrast Coronal T1 Weighted MRI

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1. Frontal lobe2. Corpus callosum3. Frontal horn4. Caudate nucleus5. III ventricle6. Optic nerve7. Pituitary stalk8. Pituitary gland9. Internal carotid artery10. Cavernous sinus11. Sphenoid sinus12. Nasopharynx

Normal calcification ： pineal body 、 cerebral falx 、 choroid plexus 、globus pallidus

Contrast enhancement ： pituitary gland 、 pineal body 、 dura 、 choroid plexus

Fig. 1.7 Post Contrast Axial MR Image of the brain

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Post Contrast sagittal T1 Wtd M.R.I.

Section at the level of Corpus Callosum

Answers39. Splenium of corpus callosum

40. Choroid plexus within the

body of lateral ventricle

41. Genu of corpus callosum

Fig. 1.11. Coronal Section of the Brain at the level of IV VentriclePost Contrast Coronal T1 Weighted MRI

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11. Cerebellar tonsil2. Cerebellar hemisphere3. IV ventricle4. Superior vermis5. Tentorium6. Posterior temporal lobe7. Choroid plexus within lateral ventricle8. Posterior frontal lobe

Abnormal changes of CT scan

a 、 hyperdense ： calcification 、 hemorrhage 、tumor 　

b 、 hypodense ： edema 、 tumor 、 cystis 、liquefactive necrosis 、 lipoma 、 fluid 　

c 、 isodense ： chronic hamorrhage 、 tumor

d 、 heterogeneous density ：

calcification

value >100Huexceed

Abnormal change of MRIA 、 T1WI ： a. hyperintensity ： fat or lipoid 、 melanin 、 constrast

medium

b. hypointensity ： edema 、 fluid 、 tumor 、 fibrosis and calcification

B 、 T2WI ： a. hyperintensity ： edema 、 fluid 、 tumor 、 b. hypointensity ： fibrosis and calcification 、

melanin

C 、 mass effect

mass

mass

evolution of hematoma and intensity of MRI　　　　　

T1WI 　　　　 　 T2WIferrohemoglobin 　　 iso- 　　　　　　 iso-ferrohemoglobin 　　 iso- 　　　　　　 hypo-methemoglobin akaryocyte 　　 hyper- 　　　　　 hypo- membranolysis 　 hyper- 　　　　 hyper-hemosiderin 　　 hypo- 　　　　 hypo- 　

A week laterAcute

methemoglobin

hemosiderin

Hydrocephalus (increased volume of cerebrospinal fluid)

1 、 obstructive hydrocephalus

2 、 communicating hydrocephalus

3 、 exterior hydrocephalus

communicating hydrocephalus

Cerebral aqueduct

obstructive hydrocephalus

exterior hydrocephalus

exterior hydrocephalus

edema

type location cause water

vasogenic edema

white matter Tumor

inflammation

trauma

hydrated water

cytotoxic edema

white matter and grey matter

acute infarction

few

vasogenic edema

cytotoxic edema