Intracranial Arteries Flashcards
Anterior circulation
ICA
anterior com
Posterior com
Posterior circulation
Basilar artery and its branches
Proximal to temination of ICA gives off what arteries
Ophthalmic artery, anterior choroidal and posterior com
Terminal bifurcation of ICA
Anterior cerebral and MCA
Horizontal or precommunicating ACA segment that courses medially above optic chiasm, joined by ACoA to contralateral A1
A1
Vertical or post communicating ACA segment that courses superiorly in the interhemispheric fissure around corpus callosum genu
A2
Distal ACA segment that courses posteriorly under inferior free margin of falx cerebri and gives off cortical branches
A3
Perforating arteries of ACA arise from
A1 and ACoA
Recurrent artery of heubner arises from
Distal A1 or proximal A2
MCA segment thar courses laterally to Sylvian fissure below anterior perforated substance, bi- or trifurcates
M1
MCA segmen that creates gentle posterosuperior turn towards lateral cerebral (Sylvian) fissure
Genu of MCA
Insular segment of MCA that courses within lateral cerebral fissure, over insula
M2
Opercular segments begin at top of insula, turn laterally in Sylvian fissure to reach overhanging frontal/ parietal/temporal operculae
M3
Cortical branches of MCAthat emerge from lateral cerebral fissure, coursing over hemispheric surface
M4
Perforating arteries of MCA cones from
M1
Courses cephalad in prepontine cistern to terminal bifurcation ventral to midbrain
Basilar artery
Basilar artery branches
AICA, Superior cerebellar arteries, pontine, midbrain perforating arteries
Basilar artery bifurcates into
PCA
Mesencephalic or precommunicating segment of PCA that lies within interpeduncular cistern, curves posterolaterallt from BA to PCoA Junction
P1
Ambient segment of PCA that extends from PCA-PCoA junction, curving around cerebral peduncles just above tentorium, above oculomotor nerve
P2
Quadrigeminal segment of PCA that extends posteromedially from level of quadrigeminal plate
P3
Cortical branches of PCA that arise from distal PCA at or just before reaching calcarine fissure
P4
Perforating branches of PCA Comes from
P1
Intracranial vertebral artery segments that enter dura near foramen magnum
V4
Vertebral arteries gives off
Anterior/posterior spinal arteries
Perforating arteries to medulla
PICA
Two watershed zones
Cortical watershed
Deep white matter watershed
Subpial confluence of cortical ACA/MCA/PCA branches
Cortical watershed
Confluence of deep cortical penetrating branches, perforating branches from circle of Willis (COW)
Deep white matter watershed zone
Perforating branches of ACA
Corpus callosum rostrum
Heads of caudate nuclei
Anterior commisure
Anteromedial putamen/globus pallidus/ anterior limb internal capsule
Cortical branches of ACA
Inferomedial frontal lobes
Anterior 2/3 of medial hemisphere surface
Perforating branches of MCA
Putamen, globus pallidus, superior half of internal capsule, most of caudate nucleus, some deep white matter
Cortical branches of MCA
Most of lateral surface of cerebral hemispheres, anterior tip (pole) of temporal lobe
Perforaring branches of PCA
Thalamus, hypothalamus, midbrain, choroid plexus
Cortical branches of PCA
Inferior surface of temporal lobe, occipital pole, posterolateral surface of hemisphere
Perforating branches of BA
all PCA Territory, pons, superior cerebellum/vermis
Perforating branches of VA
Most medulla, cerebellar tonsils, inferior vermis/cerebellar hemispheres
Imaging that shows vascular territory
Late arterial (capillary) phase of DSA with brain stain
ICA segment Contained within carotid canal of temporal bone. Surrounded by extensive sympathetic plexus
Petrous segment C2
Branches of C2
Vidian artery (artery of pterygoid canal Caroticotympanic artery
Branch of C2 that anastomose with ECA
Vidian artery
Branch of C2 that supplies middle ear
Caroticotympanic artery
ICA segment that extends from petrous apex above foramen lacerum, curving upwards toward cavernous sinus, covered by trigeminal ganglion
Lacerum C3 segment
Segment of ICA without branches
Lacerum C3
Segment of ICA covered by trigeminal ganglion posteriorly
Cavernous C4 segment
Branch of ICA with the abducens nerve inferolateral to it
Cavernous (C4) segment
Major branches of C4
Meningohypophyseal trunk
Inferolateral trunk
Branch of C4 that Supplies pituitary, tentorium and clival dura
Meningohypophyseal trunk
Branch of C4 that supplies cavernous sinus, dura/cranial nerves; anastomoses with ECA branches through foramen rotundum, spinosum and ovale
Inferolateral trunk of C4
ICA segment between proximal, distal dural rings of cavernous sinus
Clinoid segment (C5)
ICA segment extending from distal dural ring at superior clinoid to just below posterior communicating artery origin
Ophthalmic segment (C6)
Two important branches of C6
Ophthalmic artery, superior hypophyseal artery
ICA segment that extends from below PCoA to terminal ICA bifurcation info ACA, MCA
Communicating segment (C7)
ICA segment that passes between optic (CN2), occulomotor (CN3)
Communicating (C7)
Major branches of C7
Posterior communicating artery
Anterior choroidal artery
Normal variant of C2 that presents as retrotympanic pulsatile mass; should not be mistaken for glomus tympanicum tumor
Aberrant ICA
Normal variant of C2 that arises from vertical segment, crosses cochlear promontory and stapes footplate
Persistant stapedial artery
C2 normal variant that appears as Y-shaped enlarged geniculate fossa of CN7 on CT
Persistent stapedial artery
Most common carotid-basilar anastomosis
Forms trident shape on DSA, sagittal MR
Persistant trigeminal artery