This document provides an overview of angiography and the course of blood vessels supplying the brain. It describes the aortic arch and its branches, as well as the internal carotid artery in detail. The internal carotid artery is discussed in segments from the cervical segment through the cavernous segment. Common variants and anomalies are described for various segments including the persistent trigeminal artery originating from the cavernous segment of the internal carotid artery.

1. ANGIOGRAM
Presenter:Dr Srikanth
Chairperson: Dr Srijithesh
Dr Chandrajit

2. Objective
1) Understand course and branches of blood vessels supplying brain
2) Identifying vessels on angiograms
3) Knowing common variants of vessels

3. Overview
1)Aortic arch and its branches
2)Internal carotid
3)Anterior cerebral artery
4)Middle cerebral artery
5)Vertebral arteries
6)Basilar artery
7)Posterior cerebral arteries
8)Circle of Willis
9)External carotid artery

5. DSA(DIGITAL SUBTRACTION ANGIOGRAPHY)
Injection of contrast material and
real- time subtraction of pre- and post contrast images
acquisition of digital fluoroscopic images

8. Aortic arch and its branches

9. Aortic arch and its branches

11. Aortic arch and its branches
1-aortic arch
2-brachiocephalic artery
3-left common carotid
4-left subclavian artery
5-right common carotid
6-right vertebral artery
7-left vertebral artery
8-left thyrocervical trunk
9-internal mammary arteries
10-right thyrocervical trunk
11-right subclavian
12-right costocervical artery

12. Common variants of aortic arch and its major branches
1)Brachiocephalic trunk and Left CCA
share common origin
2)Left CCA arises from brachiocephalic
trunk
3)Left CCA and Left Subclavian arteries
form left sided brachiocephalic trunk
Seen about 1-2% cases
4)Left vertebral artery arises directly from
arch

13. Common variants of aortic arch and its
major branches
Brachiocephalic trunk and Left CCA share
common origin
• Most frequently encountered normal
variant
• Seen in 27% cases
• Sometimes called bovine arch

14. Common variants of aortic arch and its
major branches
Left CCA arises from brachiocephalic
trunk:
• Seen about 7% of cases

15. Common variants of aortic arch and its major
branches
Left vertebral artery arises
directly from arch
• Seen in about 0.5% cases
• Results in four vessels arising
from arch
• Arises between left CCA and left
Subclavian artery

16. Miscellaneous variants
Aortic spindle:
• Circumferential bulge just beyond
ductus
• Junction between isthmus and spindle
is marked by inferior indentation
• should not be mistaken for dissection

17. Miscellaneous variants
Ductus diverticulum:
• Focal bulge along anteriomedial aspect of
aortic isthmus
• Seen in 9% adults
• In contrast to an aortic pseudoaneurysm,
which usually forms sharp margins with the
aorta, ductus diverticulum usually appears as
a smooth focal bulge with gentle obtuse
angles with the aortic wall

18. Aortic arch anomalies

19. Aortic arch anomalies
Left aortic arch with aberrant right subclavian
artery:
• Most common congenital arch anomaly
• Prevalence-0.4-2%
• Right subclavian is last branch to arise from
aorta
• may arise from a dilated diveriticulum like
structure-Kommerell diverticulum
• Not associated with congenital heart disease
Cause dysphagia lusoria by esophageal
compression(arteria lusoria)

20. Left aortic arch with aberrant right subclavian artery

21. Internal carotid artery
Origin:
• From common carotid by
bifurcation at level of C3-C4
vertebra
• Initially lies laterally and then
courses medially crossing
external Carotid artery

22. Course of ICA
CAROTID
CANAL

23. Course of ICA

24. Segments of ICA
C1-Cervical segment
C2-Petrous ICA
C3-Lacerum
C4-Cavernous ICA
C5-Clinoid segment
C6-Ophthalmic segment
C7-Communicating
Segment
CAROTID
BULB
ASCENDING
SEGMENT
CERVICAL ICA
Lateral view

26. AP VIEW LATERAL VIEW

27. Video

28. Internal carotid artery
Cervical segment(C1)
Parts:
Carotid bulb
Ascending cervical ICA
Course:
• Common carotid bifurcates at C3-
C4
• ICA is initially posterolateral then
becomes medial to ECA
Branches: NIL
Lateral
Antero-
posterior angio

29. Internal carotid artery
Cervical segment(C1)
Normal variants:
1)High bifurcation(up to C1)
or
low bifurcation(up to T2)
2)Medial origin-
• 10% pts
• can present as retropharyngeal
pulsatile mass
3)Tortuous course
Low bifurcation at C7 level-oblique anteroposterior angio
ICA

30. Antero-posterior view-medial origin
of ICA
Antero-posterior view-Tortuous
course of ICA

31. Internal carotid artery
Cervical segment(C1)
Anomalies:
1)Anomalous origin:
both internal and external carotids arise directly from aortic arch
2) Agenesis:
• 0.01%
• unilateral
• differentiated from acquired ICA occlusion–absent carotid canal on side of
agenesis
• increased chances of aneurysms
3.Hypoplasia
4.Duplication/fenestration
5.Anamolous branches
6.Carotid-basilar anastomosis:
• Persistent hypoglossal artery
• Persistent Proatlantal arteriy

32. Hypoplastic ICA
Lateral view of common carotid-
hypolplastic ICA
Axial fat
saturated MR
Scan –Absent
flow void in right
ICA
CT Scan through skull Base-absent
right carotid canal

33. Cervical segment(C1)
• Anamolous branches:
Includes the vessels that normally
originate from
-ECA :ascending pharyngeal and
occipital arteries
-other segments of ICA like vidian
artery
-vertebrobasilar circulation like
cerebellar arteries
Lateral view- Occipital artery arising from ICA

34. Carotid basilar anastomosis

35. Carotid basilar anastomosis
1. Posterior communicating artery: connects ICA to
Posterior cerebral arteries
2. Persistent trigeminal artery: courses along trigeminal
nerve
connects Cavernous ICA with Basilar art
3. Persistent Otic artery: courses along 8th cranial nerves
connects petrous ICA with Basilar art
4. Persistent Hypoglossal artery: courses along 11th cranial
nerve connects cervical ICA with Basilar art at C1-C2
vertebral level
5. Poatlantal intersegmental artery: connects cervical ICA
with Basilar artery at C2-C3 vertebral level

36. Persistent hypoglossal artery
• Hypoglossal artery passes through hypoglossal
canal
• Associated with absence of vertebral/PCoM

37. Persistent hypoglossal artery
Axial Bone CT-enlarged hypoglossal
canal on left side
3D MIP MRA-Persistent
hypoglossal artery on left side

38. Persistent Pro-Atlantal intersegmental arteries
Association:
one or both VA are typically hypoplastic.
Two types
Type 1:
arises from the ICA and joins the V4
segment
Type 2 :
arises from the ECA and joins the V3
segment
Both entering the skull via the foramen
magnum.
Type 1 PIA-arising from ICA

39. Internal carotid artery
Petrous ICA(C2):
Parts:
Vertical segment
Horizontal segment
Genu(knee)
Branches:
1)Caroticotympanic artery:
• supply middle ear, anastomoses with inferior
tympanic artery (branch of ascending
pharyngeal)-ECA
• Arises from genu
2)Vidian artery(artery of pterygoid canal)
arises from horizontal segment
anastomoses with ECA branches

40. Petrous ICA
Lateral view AP View
Inverted L Shape of petrous segment
White arrow-->lacerum segment

41. Petrous ICA
Lateral view- Vidian artery
Caraticotympanic
artery
Inferior
tympanic
artery
Asc
pharyngeal
art
In abberant ICA with agenesis of vertical segment
of petrous ICA Inferior tympanic artery
hypertrophies and brings blood to ICA

42. Internal carotid artery
Petrous ICA(C2):
Anomalies:
1)Aberrant ICA
2)Persistent stapedial artery
3)Persistent Otic artery:
• one of the rarest variants of the carotid-vertebrobasilar anastomoses
• arise from petrous ICA
• passes through the internal auditory canal to join the BA

43. Petrous ICA(C2):Anomalies
Aberrant ICA :
• It is a congenital vascular anomaly that enters the posterior middle ear
cavity(usually ICA courses anterior to middle ear cavity) from below and
hugs the cochlear promontory as it crosses the middle ear cavity
• The ICA finally resumes its normal, expected course as it joins the
posterior lateral margin of the horizontal petrous ICA.
• Present with pulsatile tinnitus
• otoscopic examination : vascular- appearing retrotympanic mass
• Biopsy may result in fatal haemorrhage

44. Aberrant petrous ICA
• Narrowing at entry into inferior
tympanic canaliculus
• Posterior and lateral course

45. Petrous ICA(C2):Anomalies
Persistent Stapedial Artery.
• embryonic stapedial artery persists postnatally.
• discovered incidentally at imaging or at surgery.
• arises from the C2 (petrous) ICA at the genu
• The PSA passes through the stapes footplate and doubles the size of the
anterior (tympanic) facial nerve segment
• . Intracranially, the PSA becomes the middle meningeal artery (MMA).
Pathognomonic imaging findings
• (1) the absence of the foramen spinosum (because the MMA arises from
the PSA, not the ECA)
(2) an enlarged tympanic segment of the facial nerve
• A PSA is often—but not invariably—associated with an Aberrant ICA

46. Persistent Stapedial Artery
Absent
foramen
spinosum

47. LACERUM ICA(C3)
• Small segment that extends from
petrous apex above foramen lacerum
curving upwards and then becomes the
cavernous segment
• Covered by trigeminal ganglion
• No branches

48. CAVERNOUS ICA
• Starts from petrous apex
• Terminates at its entrance into intracranial
subarachnoid space adjacent to anterior
clinoid process.
• Covered by trigeminal ganglion posteriorly.
Segments
• Ascending (posterior vertical )
• Posterior genu
• Horizontal
• Anterior genu
• Anterior vertical

49. CAVERNOUS ICA
Branches:
1)Meningohypophyseal artery:
• arises from the posterior genu
• Supplies- pituitary gland, tentorium, and clival dura
2)Inferolateral trunk:
• arises from the lateral aspect of the intracavernous ICA
• Supplies- cranial nerves and Cavernous Sinus dura.
• anastomoses freely with branches from the ECA that arise in
the pterygopalatine fossa.
• This important connection between the external and internal
carotid circulations may provide a source of collateral blood
flow in the case of ICA occlusion.

50. CAVERNOUS ICA
Lateral view Submento vertex viewAnteroposterior view

51. CAVERNOUS ICA
Normal Meningiohypophysial
branch
Enlarged Meningiohypophysial trunk
supplying clivus meningioma
Lateral view of carotid Angio

52. Anomalies of C4 ICA
Persistent trigeminal artery:
• Most common of the persistent
embryonic carotid-basilar anastomose
• Identified in 0.1-0.2%
• PTA arises from posterior genu of
cavernous segment of ICA

53. Persistent trigeminal artery
Saltzmann type I:
• PTA joins the basilar artery between the superior cerebellar arteries and
anterior inferior cerebellar arteries.
• The basilar artery proximal to the junction is usually hypoplastic
• PCoAs are absent
• PTA supplies the entire vertebrobasilar system distal to the anastomosis.
Saltzmann type II:
similar to type 1 but PCoAs are present and supply the posterior cerebral
arteries
Saltzmann type III :
which directly joins to the cerebellar artery.

54. Anomalies of C4 ICA
Persistent trigeminal artery
Importance of PTA:
• Prior to transsphenoidal surgery for pituitary
adenoma as PTA passes laterally to dorsum
sella /has intrasellar course
• Nearly one-quarter of all PTAs have associated
vascular abnormalities, such as saccular
aneurysm, moya moya, aortic coarctation, and
arterial fenestrations.
• Sagittal CTA and MRA show a "Neptune's
trident" configuration
Neptune's trident sign-
PTA with vetical and horizontal
segments of cavernous ICA

55. Persistent Trigeminal artery
Saltzman type 1:
Absent PCoM

56. C5 ICA(clinoid segment)
• Starts distally to cavernous
sinus
• Ends as near anterior
clinoid process
• No important branches
ANTERIOR
CLINOID

57. Ophthalmic segment(C6)
• Extends from anterior clinoid to
just below posterior
communicating artery (PCoA)
origin
Branches
• Ophthalmic artery
• Superior hypophyseal artery
superior hypophysial
branch

58. Ophthalmic segment(C6)
Ophthalmic artery

59. Superior hypophyseal artery
• Arises from posteromedial aspect of
supraclinoid ICA
Course – across the ventral surface of
optic chiasma
• Terminates- pituitary stalk and gland
• Supplies – anterior pituitary ,
Infundibulum , optic nerve and chaisma
Anastomose - with hypophyseal branch
from the contralateral ICA forms plexus
– superior hypophyseal plexus
• DSA – usually not visualized if not
enlarged

60. Communicating segment(C7)
• Begins just proximal to origin of posterior communicating artery
and ends by dividing into anterior and middle cerebral arteries
• Passes between optic nerve and oculomotor nerves
Branches:
1)Posterior communicating artery
2)Anterior choroidal artery

61. Communicating segment(C7)
Posterior communicating artery:
Origin
posterior aspect of l ICA just below anterior
choroidal artery
Course
Posterlaterally above the oculomotor nerve
to join posterior cerebral artery
Branches
Anterior thalamo-perforating arteries
Supplies -optic chiasma, pituitary stalk ,
thalamus , hypothalamus.
PCoM
Opthalmic
artery
Ant chor Art
Lateral view

62. Communicating segment(C7)
Anterior Choroidal artery:
Arises few mms above PCoA ,from postero-medial aspect of
supraclinoid ICA
Has 2 segments
1)Cisternal segment
courses posteromedially in suprasellar cistern below
optic tract and superomedial temporal lobe uncus
2)Intraventricular segment
enters temporal horn by turning sharply laterally-Plexal
point

63. Communicating segment(C7): Anterior Choroidal artery

64. Communicating segment(C7): Anterior Choroidal artery
Supplies
• Choroidal plexus of lateral ventricle ( temporal horn and atrium )
• Optic tract and cerebral peduncle
• Uncal and para-hippocampal gyri of temporal lobe .
• Thalamus and posterior limb of internal capsule.
Anastomoses –
with LPChA and MPChA (posterior choroidal arteries)

65. Anterior Choroidal artery
Plexal point
Lateral view

66. Communicating segment(C7)
Variants:
PCoA:
1)Hypoplasia-seen in upto 1/3rd of
cases
2)duplication/fenestration-rare
3)Fetal origin of PCA
4)Infundibular PCoA:
• Seen in 5-15% cases
• Should be 2 mm or less
• Funnel shaped , conical
• PCoA arises from apex of
infundibulum

67. • Parts:
• A1(precommunicating segment): from its
origin to the anterior communicating artery
(AcomA)
• A2 (infracallosal segment) - runs into the
interhemispheric fissure upward in front of
the lamina terminalis to the genu of the
corpus callosum
• A3 (precallosal segment) - curves around the
genu of the corpus callosum,
• A4 (supracallosal segment) - It runs
posteriorly in the pericallosal cistern, above
the surface of the corpus callosum, toward
the splenium.
Anterior cerebral artery

68. Branches:
Perforating branches
1. Medial lenticulostriate arteries
2. Recurrent artery of Heubner
3. Callosal perforating artery
Anterior cerebral artery

69. Anterior cerebral artery
Branches:
Cortical branches:
1. Orbitofrontal
2. Frontopolar
Terminal Branches
1)Pericallosal
2)Callosomarginal

70. Anterior cerebral artery
AP View
A1
A2
Lateral view

71. video

72. Variants:
• A1 hypoplasia
Anomalies:
• Infraoptic origin of ACA-associated with
high prevalence of aneurysms(40%)
• Bi -hemispheric ACA
• Azygous ACA
• Persistent primitive olfactory artery

73. A1 hypoplasia

74. BIHEMISPHERIC ACA
Differentiated from
Azygous ACA by
hypoplastic
contralateral A2
Seen in upto 7%
anatomic specimens

75. Azygous ACA
increased association
• holoprosencephaly,
• aneurysms
• neuronal migration anomalies

76. Persistent primitive olfactory artery
• Hypoplastic proximal ACA takes
a very long anterior and
inferomedial course along the
ipsilateral olfactory tract just
above the cribriform plate. It
then makes a tight
posterosuperior "hairpin" turn
to continue as the normal distal
ACA.
• Long ACoA and absent
Recurrent art of Heubner
• associated with saccular
aneurysm, usually at the
"hairpin" turn

77. Middle cerebral artery
Parts:
M1-Horizontal segment
M2-insular segment
M3-opercular segment
M4-cortical branches

78. Branches:
M1-lateral lenticulostriate arteries
-anterior temporal artery
Cortical branches

79. Middle cerebral artery

80. M1
genu
M2(Insular)
Recurrent art of
heubner
Lenticulostriate art
Middle cerebral artery

81. Sylvian point and sylvian triangle
-superior insular line should lie half way
between petrous ICA and inner table of
skull-displacement or deformation usually
indicates intracranial mass

82. VIDEO

83. Middle cerebral artery
VARIANTS:
Less frequent and include-
• Fenestration and duplication
• Single trunk
• Accessory arteries

84. Vertebro-basilar system
Vertebral artery:
Parts-
V1(Extraosseus segment)-From
Subclavian artery to C6
V2(Foraminal segment)-C6 to C1
V3(Extraspinal segment)-exit of C1 to
foramen magnum
V4(Intradural segment)-foramen magnum
to basilar junction

85. Course of vertebral artery

86. Branches of vertebral artery:
• Cervical branches(spinal and muscular)
• Meningeal branches(anterior and posterior meningeal
)
• Intracranial branches
Anterior and posterior spinal arteries
PICA(Posterior inferior cerebellar artery)
Posterior spinal :
Arises from either vertebral artery (25%)or
PICA(75%)
PICA segments :
anterior medullary ,
lateral medullary,
posterior medullary ,
Supra tonsillar segment
Ant spinal arte
PICA

87. AP VIEW LATERAL VIEW
C2
veretebra
C1 Vertebra
Foramen
magnum
Vertebral artery

88. Lateral view-PICA course
Ant spinal
Posterior
meningeal Art
PICA

89. Vertebral artery
Normal Variants :
• Variation in size:
75%cases- left vertebral dominant(large) and 25% cases right
vertebral is large i.e., dominant
• Vertebral artery terminates as PICA
Anamolies:
Direct origin from aortic arch-5% cases
PICA origin below foramen magnum
Fenestration and duplication

90. Lateral view-Vertebral artery
ending as PICA
Ant spinal
art
Post spinal art
Extracranial origin of PICA

91. AP View-Fenestrated
vertebral artery

92. Basilar artery:
• Formed at Jn of pons and medulla
• Terminates in interpeduncular cistern by
dividing into PCAs
• Avg length-3 cm
Branches:
1)Labyrinthine-
BA(16%),SCA(25%),AICA(45%)
2) Pontine perforating arteries
3)Anterior inferior cerebellar arteries
4)Superior cerebellar arteries
5)Posterior cerebral arteries

93. Lateral view
Rt & Lt AICA
Looping of AICA towards
IAC-creates M or N
pattern

94. Basilar artery
Normal Variants:
1)Common origin of AICA with PICA(AICA-PICA Trunk)
2)Accessory AICA
3)Multiple SCA’s
Anomalies
1)Duplication /fenestration of basilar artery
2)Anomalous origin of cerebellar arteries (AICA VA/Cavernous ICA.
SCA - ICA/PCA)
3)Persistent carotid basilar embryonic connection

95. AP view-double SCA on left side
AICA-PICA trunk on right side
AICA with
dip into IAC
PICA

96. AP View-fenestrated Basilar artery
A small aneurysm at basilar bifurcation SCA origin from P1 of PCA

97. Non fused Basilar artery

98. Posterior cerebral artery
• PCA origin from bifurcation of
basilar artery in interpeduncular
cistern.
• Lies above oculomotor nerve.
• Circles midbrain above
tentorium cerebelli.
Segments:
P1(Pre-communicating segment)
P2(ambient segment)
P3(Quadrigeminal segment)
P4(Calcarine segment)

99. Branches:
Perforating Branches
Thalamoperforating arteries(From P1)
Thalamogeniculate arteries(From P2)
Peduncular perforating arteries(From P2)
Ventricular and choroid plexus branches
Medial posterior choroidal artery(MPChA) (From P1)
lateral posterior choroidal artery(LPChA) (From P2)
Cerebral arteries
1. Anterior Temporal artery
2. Posterior temporal artery
3. Splenial branches
4. Lateral occipital artery- anterior/middle and posterior
inferior temporal arteries
5. Medial occipital artery- pareito occipital artey
-calcarine artery
Posterior cerebral artery
P2
P4

100. Posterior cerebral artery
1-ANTERIOR TEMPORAL
2-POSTERIOR TEMPORAL
3-LATERAL OCCIPITAL ARTERY
4/5/6-ANT/MID/POST-INFERIOR
TEMPORAL
7-SPLENIAL ARTERY
8-MEDIAL OCCIPITAL
9-PARIETO OCCIPITAL ARTERY
10—CALCARINE ARTERY

101. Posterior cerebral artery
Lateral view –early arterial
1-perforating arteries
2-anterior temporal
3-medial posterior choroidal
4-lateral posterior choroidal
5-splenial branches
6-posterior inferior temporal
artery
7-calcarine artery
8-parieto occipital artery
Mid arterial phase
P1 P2 P3
P4

102. Posterior cerebral artery
AP Towne view -early
arterial
1-Thalamoperforating
arteries
2-P1
3-P2
4- temporal arteries
5-parieto-occipital
artery
6-Calcarine artery
AP View-early phase showing P3
bifurcation

103. Posterior cerebral artery
Lateral view-late arterial phase
AP View-Late arterial phase
Arrows indicate
choroid blush

104. Posterior cerebral artery
Variants:
Embryonic/fetal origin of PCA:
• Usually P1 segment is larger than ipsilateral PCoA
• In 20%cases P1 segment is smaller than PCoA and blood supply to
occipital lobe is received from ICA via PCoA instead of vertebro basilar
system
• Should be distinguished from PCA occlusion which is uncommon
though.
• Injecting ipsilateral ICA confirms Fetal PCA

106. Posterior cerebral artery
NORMAL PCA Partial fetal PCA
Complete Fetal
ACA
CAROTID Angio lateral
view with PCA origin
from ICA
Partial fetal PCA Complete fetal PCANORMAL PCA

107. Posterior cerebral artery
Other anomalies associated with PCA
• Persistent carotid basilar anastomosis-persistent trigeminal artery
,pro atlantal intersegmental artery
• Anamolous origin of PCA branches from ICA

108. Circle of Willis
• Anastomotic ring that surrounds the
basal brain structures and connects
the anterior and posterior
circulations with each other
• Source of potential collateral blood
flow to the occluded territory.
• COW has 10 components
Anterior Posterior
circulation
2 B/L ICAs
2ACAs
Unpaired ACoA
anteriorly
Posterior
circulation
Basilar
bifurcation
2 PCAs from Bas
B/L PCoAs

109. Circle of Willis
MRA-Submento verex view
CT

110. Circle of willis-Branches
ACAs
ACoAs
PCoA
Basilar artery
PCA’s
• Medial lenticulostriate arteries
• Recurrent artery of Heubner
• Perforating branches
• median artery of corpus callosum
• Anterior thalamo perforating
arteries
• Posterior thalamoperforating arteries
• Thalamogeniculatearteries

111. Circle of willis-variants
• Complete COW –only 20 – 25%
• Posterior circle anomalies – 50% anatomy
specimens and PCoA most commonly
effected
1) Hypoplasia of 1 or both PCoA – 34%
2) Fetal origin of PCA from ICA
• Anterior circle anomalies-
1)Hypoplasia or absent A1 ACA segment.
2)Absent , duplicate or multichannel
ACoA – 10-15%
Absent ACoA
Hypoplastic A1

112. External Carotid artery
• Smaller of the 2 carotids.
• Origin anterior and medial to
ICA.
• Supplies the extracranial
structures

113. External Carotid artery-Branches
ANTERIOR POSTERIOR MEDIAL TERMINAL
• Superior thyroidal
artery
• Lingual artery
• Facial artery
• Occipital artery
• Posterior auricular
• Ascending
pharyngeal
• Maxillary artery
• Superficial
temporal

114. External Carotid artery-Branches
Posterior
branches

115. External Carotid artery-Branches
1-superior thyroid
2-lingual artery
3-facial artery
4-ascending pharyngeal artery
5-main ECA
6-Occipital artery
7-posterior auricular artery
8-maxillary
9-middle meningeal artery
10-superficial temporal
11-transverse facial artery
12-ascending palatine(facial artery
branch)
Lateral view-CCA angiogram
late arterial phase
AP View-CCA angiogram
early arterial phase

116. REFERENCES
1)Osborn Diagnostic cerebral angiography
2) Boris Bradac text book of Cerebral Angiography