This document provides an overview of the history and anatomy of neuroimaging modalities. It discusses pioneers in X-rays, CT, MRI, and neuroradiology. It then describes the appearance of brain structures on different imaging sequences and outlines key anatomical regions including lobes, sulci, ventricles, cisterns, and CSF spaces. Hounsfield units and densities of brain tissues on CT are defined.

2. HISTORY
• Roentgen – X rays
• CT (computerized tomography)–
Dr.Godfrey Newbold Hounsfield
English electrical engineer
1972 – discovery
1979 – awarded the Nobel Prize
for Physiology or Medicine
The Godfrey Hounsfield Chair in Radiology

3. • MRI (magnetic resonance imaging)
Dr.Paul Lauterbur (American)
Sir Peter Mansfield (British)
The Nobel Prize in Physiology or Medicine in 2003

4. • Walter Dandy (1918) - introduction of
ventriculography.
• Arthur Schuller (1874-1957)
• Juan M. Taveras (1919-2002) –
Father of neuroradiology
Father of neurology – Jean-Martin Charcot
Father of neurosurgery - Harvey Cushing

5. DESCRIPTION Approx. HU DENSITY
Calcium > 1000 Hyperdense
Acute blood 60-80 Hyperdense
Grey matter 38 (32-42) Hyperdense
White matter 30 (22-32) Hyperdense
CSF 0-10 ISODENSE
Fat -30 to - 100 Hypodense
Air - 1000 Hypodense
Hounsfield units represent logarithmic scale of CT density.
Pure water has an HU value of ‘0’.
Current CT scans measure from – 1204 to + 3407.
Patricio S Espinaso , FOCUS ON NEUROIMAGING – Volume 1 (2009)

8. • FORAMINA
• DURAL ATTACHMENTS
• CEREBRAL HEMISPHERES
• VENTRICULAR SYSTEM
• CISTERNS
• DIENCEPHALON and LIMBIC SYSTEM
• BRAIN STEM
• COMISSURES OF BRAIN

9. FORAMINA
• Jugular foramen
• F. ovale (4)
• F. rotundum
• F. spinosum
• Carotid canal (5)
• F. magnum (7)
• F. lacerum (9)
• Hypoglossal canal (11)
11

10. A Foramen ovale
B Foramen spinosum
D Hypoglossal canal
G Clivus
H Carotid canal
J Foramen magnum

11. DURAL ATTACHMENTS
It forms folds separating the components of brain.
• Cranial dura – outer endosteal layer.
inner periosteal layer.
• Falx cerebri
sickle shaped & double layered.
attachments – anterior : frontal bone – crista galli
posterior : tentorium
margins
free margin lies above corpus callosum.

12. • Tentorium cerebelli
attached margins – clinoids and petrous apex.
free margin is ‘U’ shaped.
tent shaped.
• Diaphragma sella – circular dural
fold which forms roof of sella turcica
• Falx cerebelli

14. • On axial CT , structures medial to line of tentorial
edge are infratentorial and those lateral are
supratentorial.

16. CEREBRAL HEMISPHERES
• 4 lobes are present in each hemisphere. They are
demarcated by fissures.
• Each lobe is again divided into gyri by sulci . They are
named accordingly.
• Anatomy of cerebral hemispheres and mid brain – T1 W
MRI.
• Internal grey - white matter areas – T2 W MRI.
• In Cerebral hemispheres , white matter above the level of
lateral ventricles is called centrum semiovale

19. FISSURES
1. Central sulcus
2. Sylvian fissure
3. Calcarine sulcus (temporo-occipital fissure)
4. Parieto-occipital fissure :
Seen medially. Better seen on midline saggital MRI.

20. CENTRAL SULCUS (Rolandic fissure)
AXIAL :
1. Tracing from superior frontal sulcus.

21. 2. Similarly interparietal sulcus intersects post
central sulcus
3. Precentral : Post central gyral grey matter
thickness = 1.5 :1
4. Peri rolandic cortex more hypointense on FLAIR.

22. MEDIAL SAGGITAL :
By tracing cingulate sulcus to its posterior limit , where it
forms marginal sulcus.

23. LATERAL SAGGITAL
Into Inferior frontal gyrus, sylvian fissure forms Y shaped
sulcus . Behind it is precentral sulcus.

24. SYLVIAN FISSURE (lateral fissure)
• Begins on inferior surface and extends laterally b/w
infr. frontal and supr. temporal lobe.
• Parts – Stem and 3 rami
anterior ramus
ascending ramus
posterior ramus

28. Parieto-occipital sulcus

29. Calcarine sulcus

30. FRONTAL LOBE
Anterior to central sulcus and supr. to sylvian fissure.
1. Precentral gyrus
2. Lateral surface – supr. frontal gyrus
middle frontal gyrus
infr. frontal gyrus
3. Inferomedial – Gyrus rectus
4. Inferolateral – Orbital gyri

36. Functional divisions of frontal lobe
• Motor area
• Pre motor area
• Supplementary motor area
• Frontal eye field
• Broca’s area
• PRE FRONTAL CORTEX
- DLPFC – working memory
executive functions
- OFC – emotions
- MPFC – auditory and visual ass.

37. PARIETAL LOBE
• Parieto-occipital differentiation.
• Parieto-temporal differentiation ??
1. Post central gyrus
2. Superior parietal lobule
3. Inferior parietal lobule

40. TEMPORAL LOBE
Sylvian fissure and calcarine sulcus - borders
1. Superior temporal gyrus -
Heschl gyrus – floor of sylvian fissure & above supr.
temporal gyrus. It is found on ‘flat top’ surface of supr.
temporal gyrus.
2. Middle temporal gyrus
3. Inferior temporal gyrus

46. INFERIOR SURFACE
Temporal lobe
• Parahippocampal gyrus – terminates at temporal
tip and curls backwards to form uncus.
• Lingual gyrus
• Fusiform gyrus
• Inferior temporal gyrus

52. Frontal lobe
• Gyrus rectus.
• Orbital gyri.
• Olfactory sulcus.

54. Line diagramn

56. MEDIAL SURFACE
• Cingulate gyrus – starts beneath genu of C.Callosum till splenium.
• Callosal sulcus
• Cingulate sulcus

57. • Paracentral lobule – surrounds medial projection of
central sulcus.
Medial extention of motor and sensory cortex.
- anterior
- posterior
• Cuneus – b/w parietooccipital fissure and calcarine
sulcus.
• Precuneus – b/w parietooccipital fissure and
marginal sulcus.

61. INSULA
• A pyramidal shaped submerged cortex is known as insula.
• It is visualised when the opercula of lateral sulcus are
retracted.
• Limen
• Circular sulcus
• Central sulcus
• Short and lond gyri

63. • Apex of insula is limen , and is directed below and to front.
• Circular sulcus separates insula from different opercula.
• Central sulcus is placed obliquely and divides insula into antr.
short gyri and postr. long gyrus

65. Insula figures

67. CSF SPACES
• Choroid plexus
mainly in lateral ventricles and partly in 3rd and 4th
ventricles.
Choroid plexus within the atrium of lateral ventricle
and occasionally in 4th ventricle –
‘HYPO’ on CT and MRI.
On CECT, there is homogenous enhancement of choroid
plexus.

69. VENTRICULAR SYSTEM

70.  Lateral ventricles – Telencephalon ( cerebral hemisheres)
 3rd ventricle – Diencehalon
 Sylvian aqueduct – Mesencephalon (midbrain)
 4th ventricle – hind brain (pons+medulla)

71. • Saggital and Coronal T1 weighted MRI – accurate
assessment of ventricles and C. callosum
• Mid Saggital section – for shape and configuration
of Aqueduct of Sylvius.
• CSF intensity on MRI

72. Lateral ventricle
• Parts :
Horns – Frontal, Occipital and
Temporal.
Body
Trigone / Atrium
• Relations :
supr. – C. callosum
infr. – choroid plexus, thalamus
and hippocampus
lat – caudate nucleus
med – S. pellucidum and fornix

73. Septum pellucidum : seperates lateral ventricles (FH and
body).
• It is a midline triangular sheet attached above to
C.callosum and postr.ly to fornix.
• It has 2 laminae with narrow cavity.
( cavum SP – due to seperation of 2 laminae. In 10% adults )

74. • Radiology –
Axial MRI / CT : frontal horns separated by
S. pellucidum and posteriorly lateral ventricles diverge
and pass into temporal and occipital horns.
Saggital MRI : ‘C’ shaped , curving round the
thalamus.

76. • Radiology –
Axial MRI / CT : frontal horns separated by
S. pellucidum and posteriorly lateral ventricles diverge
and pass into temporal and occipital horns.
Saggital MRI : ‘C’ shaped , curving round the
thalamus.
Coronal : frontal horns – inverted triangle
body – flattened
temporal horns – like ‘C’ on its sides.

78. Foramen of Monro
• relations –
antr.– fornix, S. pellucidum.
postr. – choroid plexus , thalamus
• To differentiate frontal horn
from body of LV.
‘Y’ shaped.

79. 3RD VENTRICLE
• Anterior wall – anterior commisure
lamina teminalis
• Posterior wall – suprapineal recess
pineal body with pineal recess
habenular comissure
posterior comissure
aqueduct of midbrain
• Roof - fornix Floor – optic chiasma
choroid plexus Infundibulum
tuber cinereum
• Lateral wall - thalamus mamillary bodies

82. • Radiology –
Axial MRI / CT - narrow cleft
Saggital MRI – elongated and complex curved shape
with upward, backward & downward arc.

83. Aqueduct of sylvius
• Relations – antr. , Postr.
• Communications
• Radiology –
Saggital MRI: concavity that curves downward
and forward towards the floor of 3rd ventricle.

85. 4TH VENTRICLE
• 4 angles - rostral, caudal , two lat.
• Relations - antr.
postr.
lateral
inferior
• Communications
supr. and infr.
postero infr.
postero lat.

87. Radiology
• Axial MRI / CT – ‘kidney bean’ turned on its side.
• Saggital MRI - mid point of line drawn b/w T. sella
and trocula should intersect middle of 4th
ventricle.
• Coronal MRI – elongated rhomboid shape

90. CISTERNS
• Where brain and skull are not closely
apposed, arachnoid and pia separate – and form
cisterns .
• Mainly present at base of brain, around brain stem and
free edge of tentorium.
1. Posterior fossa cisterns
2. Basal cisterns
3. Mesencephalic cisterns
4. Lateral superior cisterns

91. POSTEROR FOSSA CISTERNS
1. Medullary cistern : antr. to medulla
VA, spinal A, 12th nerve
2. Pontine cistern : b/w pons & clivus
vertibrobasilar A, AICA & SCA origin, 6th nerve
3. Cisterna magna : b/w medulla & postroinfr. cerebellum
PICA, 9th 10th 11th cranial nerves
(Triangular in saggital section)

93. 4. Supr. cerebellar cistern : b/w tentorium & cerebellar H
SCA, supr. vermian veins.
5. CP angle cisterns : bounded by cerebellum, pons and
tentorium.
AICA, 5th 7th 8th cranial nerves

94. SUPRASELLAR / BASAL CISTERNS
1. Interpeduncular cistern : b/w Cerebral peduncles
Basilar A, thalamoperf. A .
2. Chiasmatic / Suprasellar cistern : above sella
ICA, MCA & ACA origin, P comm. A,
antr. Choroidal A; prox. basal V of Rosenthal;
optic chiasma & tract; hypothalamus, infundibulum.
(extends from infundibulum to postr. surface of frontal
lobe and lies b/w uncus on either side.
Contains circle of willis and so SAH seen)

96. MESENCEPHALIC CISTERNS
1. Ambient cistern : surrounds mid brain. Connects
Suprasellar, pontine & quadrigeminal cisterns.
PCA, BA, SCA, 6th cranial nerve .
2. Quadrigeminal cistern : behind pineal & Q plate
Connects ambient and supr. cerebellar cisterns.
Pineal gland, postr 3rd ventricle, V of Galen, V of Rosenthal.
3. Velum interpositum : above 3rd ventricle; below fornix
& C.callosum (antr. continuation of Quadrigeminal
cistern)
Internal cerebral V, Choroidal arteries .

97. LATERAL SUPERIOR CISTERNS
1. Sylvian fissure : b/w insula & opercula.
connects medially with suprasellar cistern
MCA, supr. middle cerebral V.
2. Convexity subarachnoid space
contains cortical arteries and veins.

111. Line diagramn