Radiology Pt1 Anatomy - Head And Neck Vessels

Front 1

Branches of ECA

Back 1

S: superior thyroid
A: ascending pharyngeal
L: lingual
F: facial
O: occipital
P: posterior auricular
M: maxillary
ST: superficial temporal

Front 2

Superior thyroid artery:

Back 2

O: Anterior ECA at level of hyoid bone

B: muscular, infrahyoid, sternocleidomastoid, superior laryngeal, cricothyroid, glandular (2 branches commonly) Mnemonic - May I softly squeeze chick's glands?

S: Larynx, associated muscles and thyroid gland (ramifies across, and with inf. thyroid a.)

R: internal branch of superior laryngeal nerve accompanies superior laryngeal branch through hyothyroid membrane and to larynx.

V: 20% arise from carotid bifurcation
10% arise from CCA

Front 3

Ascending pharyngeal artery:

Back 3

O: posterior ECA

B: 2 major trunks - pharyngeal and neuromeningeal
Pharyngeal trunk branches - superior, middle and inferior
Nureomeningeal trunk branches - hypogossal, jugular. Also branches to clivus and odontoid arch.

S: Pharyngeal spaces via PT
NMT - posterior fossa meninges and CNXII via hypoglossal branch (through hypoglossal canal)
CN IX, X, XI and meninges of IAC, inf. petrosal sinus and sigmoid sinus (via jugular foramen)

R: -
V: -

Front 4

Lingual artery

Back 4

O: Anterior ECA @ C3

B: Tonsillar, hyoid and tongue branches

S: oral floor and tongue

R: crossed by hypoglossal nerve centrally

V: can arise with the facial a. as the linguofacial trunk

Front 5

Facial artery

Back 5

O: Anterior ECA behind mandibular ramus

B: 4 cervical branches - submental, tonsillar, glandular, ascending palatine
4 facial branches -
sup and inf labial, lateral nasal, angular

S: Muscles of mastication, nasalis muscle, submandibular gland, tonsil and soft palate.

R: Crossed by facial nerve. Anastamoses distally with opthalmic artery.

V: Linguofacial trunk

Front 6

Occipital artery

Back 6

O: Posterior ECA opposite maxillary artery, near lower margin of posterior digastric belly.

B: Sternocleidomastoid branch, auricular branch, mastoid branch, descending branches and occipital branches

S: Scalp over occipital bone

R: Terminal portion accompanied by the greater occipital nerve (branch of cervical spinal nerve 2)

V: Stylomastoid artery arises here in 66% of people, supplying the middle and inner ear through the SM foramen.

Front 7

Posterior auricular artery

Back 7

O: Posterior ECA above digastric. Ascends between styloid process and parotid.

B: -

S: scalp posterior to ear, pinna, parotid gland.

R: ascends beneath parotid, anterior to styloid process.

V: Stylomastoid a. arises here in 33%, supplying middle and inner ear through the SM foramen.

Front 8

Superficial temporal artery

Back 8

O: smaller terminal branch of ECA (behind mandible, in parotid)

B: Frontal and parietal (superficial to temporal bone) branches seperate 5cm above post. zygomatic arch

S: scalp and pericranium. Parotid, TMJ, and outer ear.

R: crossed by temp. and zygom. branches of facial nerve.

Front 9

Maxillary artery

Back 9

O: Larger of terminal branches of ECA. Arises within parotid, behind mandible.

B: 3 parts (each part has 5 branches)
- Mandibular part:
Middle meningeal to dura and cranial bones via foramen spinosum.
Accessory meningeal to dura and bone via foramen ovale.
Inferior dental to lower jaw structures.
- Pterygoid part:
Branches to masseter, pterygoids, temporalis
- Pterygopalatine part (all in PtP fossa):
Superior dental a. to upper jaw structures
Infraorbital a. to orbit via infraorbital fissure
Greater palatine a. to hard palate, tonsil, gums and mouth mucous membranes via palatine canal and greater palatine foramen.
Sphenopalatine to nasal cavity supplying nose and sinuses via sphenopalatine foramen.

S: see above

R: 1 deep to neck of mandible.
2 along lateral pterygoid (either side)
3 in pterygopalatine fossa

V: -

Front 10

Left common carotid

Back 10

O: Aortic arch in front of trachea.

B: ECA and ICA

S: -

R: Anterior to trachea. Passes across to lie left of trachea at root of neck.
Medial to internal jugular vein up neck. Vagus lies between these two, posteriorly.

Lateral to trachea, oesophagus and recurrent laryngeal nerve (between O and T) at lower neck. Lateral to pharynx/larynx and recurrent laryngeal nerve cranially. Posterolateral to thyroid gland.

Posteromedial to sternomastoid and strap muscles caudally.

V:

Front 11

Right common carotid

Back 11

O: Brachiocephalic trunk behind R sternoclavicular joint

B: ECA ICA @C4

S: -

R: Along R border of trachea. Medial to internal jugular vein up neck. Vagus lies between these two, posteriorly.

Lateral to trachea, oesophagus and recurrent laryngeal nerve (between O and T) at lower neck. Lateral to pharynx/larynx and recurrent laryngeal nerve cranially. Posterolateral to thyroid gland.

Posteromedial to sternomastoid and strap muscles caudally.

Front 12

Internal carotid artery - portions

Back 12

C1, Cervical - origin to carotid canal in petrous temporal bone
C2, Petrous - from start of carotid canal to foramen lacerum. 1 branch
C3, Lacerum - from foramen lacerum to petrolingual ligament (between lingula and petrous apex of sphenoid bone). Still extradural (does not enter skull through lacerum, still surrounded by periostium)
C4, Cavernous - from cavernous sinus to proximal dural ring (periostium of anterior clinoid process). 2 branches.
C5, Clinoid - from proximal dural ring to distal dural ring (enters subarachnoid space here)
C6, opthalmic or supraclinoid - distal dural ring to PCOM. 2 branches.
C7, Communicating - PCOM to termination.

Mnemonic for branches before communicating segment:
"Apple's CMOS
ie CMiOS"
caroticotympanic
meningohypohyseal
inferolateral trunk
opthalmic
superior hypophyseal

Front 13

Internal carotid artery - Cervical portion

Back 13

O: Carotid sinus at the bifurcation.

B: none in cervical portion

R: In carotid sheath -
Anterior to sympathetic trunk, prevertebral muscles and transverse processes of C1-C3
Lateral to pharynx.
Medial to styloid process and muscles (styloglossus, stylopharyngeus), which seperate ICA from ECA

V:

Front 14

ICA - Petrous portion

Back 14

O: Carotid canal

B: Caroticotympanic artery to tympanic cavity (anastamoses with ant tympanic branch of maxillary).

R: Ascending portion in front of cochlea/tympanic cavity
Horizontal portion - seperated from trigeminal ganglion by bony canal.

V: Vidian artery (usually from ECA)
Abberent ICA - the ICA passes more posterolaterally and is seen within the hypotympanum (retrotympanic). can be mistaken for a glomus tumour.
Persistent stapedial artery - arises from vertical segment and runs along the geniculate fossa across the stapes. Terminates as middle meningeal artery (foramen spinosum is absent)

Front 15

ICA - Lacerum segment

Back 15

O: foramen lacerum

B: none

V: occasionally vidian artery comes from here

Front 16

ICA - Cavernous segment

Back 16

O: petrolingual ligament

B: meningohypophyseal trunk to ant cranial fossa dura, bone and a branch to pituitary
inferolateral trunk supplies cavernous sinus, branch to foramen rotundum and trigeminal ganglion

R: In cavernous sinus
Lateral to CN III, IV, VI and V 1 and 2.

V: Persistent trigeminal artery in 0.2-0.5%
Parallels course of CN5, connects ICA to vertebrobasilar system
....

Front 17

ICA clinoid segment

Back 17

O: proximal dural ring

B: none

R:

V: opthalmic can arise from here

Front 18

ICA opthalmic segment

Back 18

O: distal dural ring

B: ophthalmic artery
superior hypophyseal artery to infundibulum of pituitary, pars tubarius

R: horizontal, inferolateral to optic nerve

V: superior hypohyseal often arises from PCOM

Front 19

ICA communicating segment

Back 19

O: PCOM origin

B: PCOM
anterior choroidal artery, supplying some flow to most of the diencephalon and limbic system
ACA, MCA
Striate arteries to thalamus, GP and internal capsule

R: between optic and occulomotor nerve to anterior perforated substance, medial portion of the lateral cerebral fissure.

Front 20

Circle of Willis - parts

Back 20

ACOM, A1, ICA, PCOM, P1

MCA and basillar are not considered part of circle (they come off the circle)

Front 21

Circle of Willis - variations general

Back 21

Normal in only 20-35% of people.
Posterior circle anomalies are most common, present in over 50% of people.

Front 22

Anterior cerebral artery

Back 22

O: ICA termination

B: 3 parts.

R: A1 - from ICA to ACOM. Has medial lenticulostriate branches to caudate and internal capsule.
A2: From ACOM to bifurcation. Gives off recurrent artery of Heubner in 90% of cases, which runs backwards parallel to A1. This supplies the internal capsule.
Orbitofrontal artery supplying inferior frontal lobe and frontopolar artery supplying anterior pole of frontal lobe arise here.
A3:
The A3 segment is also called the pericallosal artery, which curls back over the corpus callosum. This extends in the pericallosal sulcus, and gives rise to sup and inf internal parietal arteries and the precuneal artery (supplying the precuneus - the medial part of the parietal lobe in the longitudinal fissure). Ther pericallosal also gives of the pericallosal moustache over its length - fine arteries to the corpus.
Callosomarginal branch arises from origin. It branches into medial frontal branches and the paracentral artery, which supplies paracentral cortex and gives brnaches to the cingulate gyrus below throughout its length).

V: Recurrent artery of Heubner from A1 in 10%
Absent A1 in 5-15% (unilateral ICA supply via ACOM)
Absent callosomarginal in 40-50% (branches arise from pericallosal).

Front 23

Middle cerebral artery

Back 23

O: ICA/circle of Willis

B: 4 parts

R:
M1 (sphenoidal or horizontal segment) runs from ICA to bifurcation. Supplies basal ganglia via lateral lenticulostriate branches. Also has the temporopolar artery, which supplies polar and anterolateral temporal lobe.
M2 (insular) extends from bi (+) furcation to sylvian fissure.
M3 (opercuar branches) are in Sylvian fissure.
M4 (cortical branches) leave sylvian fissure and extend up into cortex of frontal, parietal, and temporal lobes.

Frontal branches -
lateral frontobasal or orbitiofrontal artery to inferior frontal gyrus
prefrontal arteries to inferior and middle frontal gyrus. Often anastamose with pericallosal artery
pre-central or pre-rolandic arteries to posterior middle and inferior frontal gyrus, and lower pre-central gyrus.
central or rolandic arteries sit in central sulcus, to supply posterior pre-central gyrus and inferior post-central gyrus.

Parietal branches -
anterior parietal, posterior parietal branches.
angular artery is a terminal branch, to angular gyrus and supramarginal gyrus, posterior superior temporal gyrus.
temporaloccipital artery to superior and inferior occipital gyri. Often anastamoses with the PCA

Temporal branches -
Anterior temporal to polar and anterolateral temporal lobe
Middle temporal superior and middle temporal lobe
Posterior temporal in superior temporal sulcus to the posterior temporal lobe, also has several branches to the insula.

V: Bifurcates 50-75%, trifurcates 15-25% (into superior, middle and inferior divisions) and more numerous branches ~10% of the time.

Accessory MCA (second artery parallel to MCA from A1 segment) 1-4%
Duplicated MCA (double arteries from origin) 1-3%
Fenestrated MCA (splits and rejoins into 1 artery during M1 segment) in <1%

Front 24

Posterior cerebral artery

Back 24

O: PCOM

B: 4 parts

R:
P1 - Basillar to PCOM in interpeduncular cistern gives posteromedial ganglionic branches which pierce the posterior perforated substance to supply thalamus and walls of 3rd ventricle
also the posterior choroidal arteries to the tela choroidea/choroid plexus and the basal ganglia
P2 (ambient segment) in ambient cistern
P3 (quadrigeminal segment) gives posterolateral ganglionic branches to thalamus
P4 cortical segment has branches to

temporal lobe -
anterior temporal artery to the uncus and anterior fusiform gyrus
posterior temporal artery to the posterior fusiform and inferior temporal gyrus
inferior temporal arteries

Occipital lobe branches
medial occipital, supplying the cuneus and gyrus lingualis, and posterior occipital lobe via the calcerine branch, and the cuneus and precuneus via the parieto-occipital branch
Splenial supplies posterior corpus callosum, often anastamoses with the ACA.

V:foetal PCOM (dominant PCOM) in 15-20%
Artery of Percheron supplies bilateral thalami and rostral midbrain, very rare.

Front 25

Basillar artery

Back 25

O: Vertebral arteries confluence at junction between medulla and pons

B: PCAs.
Multiple pontine branches - to pons!
Anterior inferior cerebellar artery at junction between midbrain and pons supplies ant. inf. part of cerebellum. The labyrinthine artery arises from here in 85% to supply inner ear through IAM.
Superior cerebellar artery arises at the termination, below the PCA. It runs underneath the PCA around the midbrain, seperated by the occulomotor nerve. It reaches the upper surfice of the cerebellum to supply the superior cerebellum, the pineal body, anterior medullary velum, and tela chorioidea of the third ventricle.

R: rises in the central groove in front of the pons between the abducens nerve and occulomotor nerve

V: fenestrated basillar 2-5%
Labyrinthine origin on basillar (rather than AICA) in 15%

Front 26

Vertebral arteries

Back 26

O: 1st branch of subclavian arteries bilaterally. Can arise from brachiocephalic on right or aortic arch either side.

B: 4 parts
V1 - to foraman transversarium (usually C6)
V2 from FT C6 to FT of C2
V3 from C2 to the dura
V4 from the dura to the confluence

V1, V2 and V3 give
- muscular branches, including a large one from V3 to the occipital triangle. These branches anastamose with occipital and ascending pharyngeal branches.
- Spinal branches through foramina to cord

In skull (V4) gives
- anterior spinal artery which is a midline (bilateral supply) branch in front of the spinal cord, to supply the bones, dura and cord.
- posterior spinal arteries descend as 4 branches, 2 anterior to dorsal roots and 2 posterior to them
- posterior inferior cerebellar artery (largest branch) to supply the inferior cerebellum, choroid of the 4th ventricle and lateral medulla. It winds around the medulla between the origins of CN X and XI, over the inferior peduncle to the cerebellum.
-meningeal branch to the cerebral fossa and falx

R:
V1- Runs up between longus colli and scalenus anterior muscles. Anterior is internal jugular, vertebral veins, and ICA. Behind it are transverse process of C7, the sympathetic trunk and inferior cervical ganglion
V2 - Runs through froamina transversarium C6-C2. surrounded by branches of the inferior cervical sympathetic ganglion, and spinal venous plexus, which become the vertebral veins lower down. Posterior is cervical nerve trunks.
V3: passes posterior to the lateral mass of C1 in its own groove then turns upward through foramen magnum.
V4: after piercing dura it ascends in front of medulla, uniting with the ipsilateral vertebral at base of pons, in prepontine cistern.

V: Left is dominant in 80%
Posterior spinal arises from PICA in >50%

Front 27

Superior sagittal sinus

Back 27

O: Nasal vein anteriorly.

B: Recieves blood from the nasal vein, the superior cerebral veins, the diploic veins and dural veins, and posteriorly also recieves blood from the pericranium, via veins that travel through the parietal foramina

R: Midline, running from front to back, until it reaches the confluence and turns to one side (usually the right) to become the transverse sinus.

It is adjacent several venous lakes between the dura and endosteum, which contain projections of arachnoid granulations, to return CSF to the bloodstream.

Front 28

Straight sinus

Back 28

O: Confluence of the inferior sagittal sinus and great cerebral vein.

B: Recieves the inferior sagittal sinus, the great cerebral vein and the inferior vermian vein (draining the posteroinferior cerebellum)

R: runs in the tentorium where the falx attaches. At the confluence it turns (usually left) to become the transverse sinus.

Front 29

Inferior sagittal sinus

Back 29

O: Deep and medial aspects of cerebrum

R: runs in the free edge of the falx, above the corpus. Joins the great cerebral vein to form the straight sinus

Front 30

Drainage of head sinuses to neck

Back 30

Transverse - Sigmoid - Internal jugular vein

Front 31

Sphenoparietal sinus

Back 31

O: drains nose, sphenoid sinus and bone, and often the anterior temporal diploic vein (a largish vein of the middle cranial fossa)

R: runs along the free lower edge of the less wing of sphenoid to the cavernous sinus

Front 32

Cavernous sinus

Back 32

O: drains the superior opthalmic vein (through superior orbital fissure), some superficial middle cerebral veins and the sphenoparietal sinus.

R: Either side of the pituitary, although there is communication via intercavernous sinuses. Lies between layers of dura.
Superior is the optic chiasm, and the ICAs.

Within the cavernous sinus is the cavernous portion of the ICA medially, which is just medial to the CN VI nerve. Along the lateral wall are the CNIII, IV and V1, V2.

Drains to the superior and inferior petrosal sinuses

Front 33

Superior petrosal sinus

Back 33

O: Cavernous sinus

B: drains the cavernous sinus, some cerebellar and inferior cerebral veins, and veins from the tympanic cavity

R: Runs in the attached edge of the tentorium, in the superior petrosal sulcus of the PTB. Drains to the transverse sinus.

Front 34

Inferior petrosal sinus

Back 34

O: Cavernous sinus

B: drains the cavernous sinus, internal auditory veins, veins from the pons, medulla and inferior cerebellum.

R: Passes through the anterior part of the jugular foramen and drains into the superior bulb of the IJV.

Front 35

Internal cerebral vein:

Back 35

O: drains the thalamostriate vein (between thalamus and lentiform), the choroidal vein and the septal vein (s. pellucidum).

R: It courses on the underside of the corpus to the rostrum, before turning back and running along the roof of the third ventricle.

The 2 internal cerebral veins join to form the great cerebral vein.

Front 36

Great cerebral vein

Back 36

(of Galen)

O: Drains the internal cerebral vein, the basal vein (of Rosenthal), and the posterior fossa veins (ie the anterior pontomesencephalic vein, the precentral cerebellar vein etc)

R: Forms beneath the splenium of the corpus, and runs backwards in the quadrigeminal cistern, to the straight sinus.

Front 37

The basal vein

Back 37

(of Rosenthal)

O: The anterior perforated subastance, by the union of the anterior cerebral vein (follows ACA), the deep middle cerebral vein (of the insula) and the striate veins via the anterior perforated substance.

It recieves branches from the interpeduncular fossa, the inferior horn of the lateral ventricle, the hippocampal gyrus, and the mid-brain.

R: curls around the cerebral peduncles of the midbrain to join the great vein.

Front 38

Anterior choroidal artery

Back 38

O: Communicating segment ICA

S: Choroid plexus, medial temporal lobe, posteroinferior internal capsule, basal ganglia

R: Passes out the suprasellar cistern laterally, enters the temporal horn.

Front 39

Opthalmic artery

Back 39

O: Ophtalmic segment ICA

S: Nasal, ocular, orbital, muscular branches

R: Extensive anastamoses with ECA

Front 40

Caroticotympanic artery

Back 40

O: Petrous segment of internal carotid artery

S: Tympanic cavity

R: anastamoses with superior tympanic branch of internal maxillary artery

Front 41

Meningohypophyseal

Back 41

O: Cavernous segment carotid artery

S: Dorsal meningeal artery
Inferior hypophyseal artery
Tentorial artery

Front 42

Inferolateral trunk

Back 42

O: Cavernous segment carotid artery

S: Sends branches which all anastamose with various other arteries via
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen lacerum

Front 43

Superior hypophyseal artery

Back 43

O: Opthalmic segment ICA

S: pituitary

V: often arises from PCOM