http://www.musc.edu/intrad/AtlasofVascularAnatomy/images/CHAP2FIG1.j
pg
Normal carotid artery
Normal Carotid artery
bifurcation
http://
www.specialistvascularclinic.com.au/ cv
Pictorial images showing normal common
arteries and effect of the presence of plague
http://www.nhlbi.nih.gov/health/health-topics/topics/cu/
ANATOMY
Cerebrovascular
The main arteries that supply the brain and the central nervous system are the Carotid
(2)and vertebral (2) arteries running cephalad on both sides of the neck. These arise
from the aortic arch.
-On the right-the Brachiocephalic travels upwards and then branches into the right
common carotid and subclavian arteries goes through at the upper border of the
sterno-clavicular junction- supplies the brain and eyes-no extra cranial branchesintracranial segment consists of the petrous, the cavernous and the cerebral
-On the left- the left common carotid artery(CCA) travels upward from the arch behind
the sterno-clavicular joint
There are no branches on either CCA.
• CCAs divide into internal carotid arteries(ICA) and external carotid arteries(ECA), in
mid cervical region at the upper border of the thyroid cartilage.
• ECAs are superficial with eight branches- superior thyroid, the lingual, the external
and internal maxillary, occipital, facial, and transverse facial, posterior auricular,
superficial temporal arteries. The external carotid arteries do not supply the brain but
becomes important collateral pathways in case of occlusion in the ICA and Vertebral
arteries most vital to collateral circulation are those in communication with ophalmic
artery and those that intercommunicate between muscular branches and the
occipito-vertebral arteries
• The left subclavian artery is the third major branch of the aortic arch
• The vertebral arteries arise off the subclavian arteries bilaterally,
they ascend the neck along the right and left ICA, they lie within the
foramina transverse sarium of the upper cervical vertebrae and
winds and bends medially before entering the cranial cavity through
the foramen magnum. The two arteries join to form the basilar
artery
• The cerebral branches of the internal carotid arteries and vertebral
arteries join at the base of the brain to form the circle of Willis
• The circle of Willis is a unique arrangement of vessels which provide
a vital collateral network to maintain cerebral perfusion in the event
of disease
• -anteriorly formed by the right and left `anterior cerebral arteries
which are interconnected via the anterior communicating artery
and posteriorly by the right and left posterior cerebral arteries,
which are connected via the posterior communicating arteries .
• INDICATIONS
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•
•
•
•
•
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-Transient I schaemic attacks
-Cerebro-vascular accident(CVA)
-Amaurosis Fugax
Cervical bruit
-Neuralogical deficit-temporary or persisting
-Dizziness, Vertigo, headaches, fainting
Post operative surveillance
-Vertebral artery disease
-Follow up of previous noted disease
SCANNING PROTOCOL
• The patient is scanned in supine position or erect sitting in a chair for patients
with shortness of breath -elderly and obese-pronounced lordosis/curvatutre
•
•
•
•
•
Scanning all the arteries bilaterally
Common Carotid Arteries -Proximal and distal.
External Carotid Arteries - Proximal
Internal Carotid Arteries - Proximal, mid and distal
Vertebral- extra cranial- unless otherwise indicated for transntracranial imaging
•
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CFD and B-mode
Transverse and long section of CCA and ICA bilaterally
Transverse and long section of the stenosis and bifurcation
Should include images showing the brachiocephalic, subclavian,
Spectral waveform in proximal ECA and proximal , mid and distal ICA
Spectral waveform in the vertebral artery bilaterally
Transcranial Doppler(TCD)/ Transcranial colour Doppler(TCCD)
-Four main windows
1. Transtemporal. 2. Transorbital. 3.Sub Occipital. 4.Submandibular
• TRANSTEMPORAL -the following arteries are seen
-Mid cerebral artery, at 35-60mm deep from the transducer –mean
velocity of 62+/- 12 cm/s
Anterior cerebral artery, at 60-75 mm deep from the transducer 50+/11 cm/s mean velocity
Posterior cerebral artery, at 65-75 mm deep from the transducer
39+/-10 cm/s
Posterior communication artery,
Anterior communication artery, 60-65mm depth from the
transducer with a variation of
mean velocities.
Internal carotid artery
Basilar artery ( posterior beam)
• TRANSORBITAL
-Ophthalmic artery - 45-65mm deep from the transducer 20+/-10cm/s
-Internal carotid (siphon) artery 60-80 mm deep from the transducer
-60-80mm deep from the transducer 47+/- 10 cm/s mean
--velocity
• SUBOCCIPITAL
• Vertebral artery -50-85mm deep , 36+/-10 cm/s mean velocity
• SUBMANDIBULAR
• -Distal internal carotid artery, 35-70mm deep from the transducer,
39+/-10 cm/s mean velocity.
Indicatons for TCD orTCCD
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•
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Tight stenosis or occlusion of the ICA OR CCA
Presence of intracranial arterial disease
Transient ischaemic attacks with no other source of embolism
Vertebral artery disease
Arterial noise in the ear
Syncope or dizziness with head rotation
Monitoring cerebral perfusion in the intensive care unit after
stroke ,subarachnoid haemorrhage or head injury
• Studying changes in intracranial haemodynamics and emboli
during carotid endarterectomy or coronary artery bypass
grafting.
Transducer selection
Selection of the protocol on the Duplex Doppler equipment
should be –Vascular and specifically- carotid artery
3-9 MHz linear array – or curvilinear (when access to neck is
limited e.g. in short neck, intravenous lines, or tracheotomy ties)
transducer- to provide high resolution at a depth of 2-10cm
Transducer footprint-rectangular-4-5cm long –narrow 1cm wide.
PATIENT’S HISTORY
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•
•
•
Full history is undertaken – taking note of whether patient is
-hypertensive or has high cholesterol
-Diabetic
-Previous history of heart attach/ any intervention surgery like
carotid endarterectomy, coronary bypass , stent placement or
peripheral arterial revasculisation.
TECHNIQUE
• Patient in supine position –neck extended ensure patient’s
comfort
• Neck exposure –maximized- rotating the neck away from side
under examination
• In B-mode and colour Doppler the Bracheo-cephalic and
subclavian arteries examined noting any plague or
calcification-noting any tortuosity of the vessels
• The CCA is examined from proximal to distal in Longitudinal
and transverse sections-looking at the wall outline for
disease.
• Survey the carotid bifurcation into ICA and ECA proximal, mid
and distal
• Tap the temporal bone to accurately identify the ECA- observe
change in the waveform.
The ICA is examined from the bifurcation as far distally as
possible- For transcranial scanning –use of windows mentioned
above.
The vertebral artery –examined with chin extended/flexed
The colour box/sample volume is placed wide enough to get
maximum information with the angle of isonation not more
than 60degrees.
DIFFERENCIAL DIAGNOSIS
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-Vertebral artery/vertebrobasilar disease
-Carotid artery dissection
-Carotid aneurysm
-Carotid body tumour
-Moya Moya disease
-Takayasu’s arteritis
-Fibro muscular dysplasia
CRITEIA FOR DIAGNOSIS
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•
STENOSIS
PSV(cm/s)
EDV(cm/s)
16-49%
< 125
-
-
50-69%
> 125
< 110
<2
70-79%
> 270
> 110
>4
80-99%
> 270
>140
>4
Increase in mean velocity in the MCA
-120-150cm/s = minor stenosis
-150-200cm/s =moderate stenosis
->200cm/s severe stenosis
RATIO(IC/CC)
NASCET CRITERIA
Retrieved from: http://www.kup.at/journals/abbildungen/
Normal carotid artery spectral wave form
Retrieved from:
http://www.charlesbuntjer.com/chucks_research_projects_2007_12_14_
carotid_arteries.htm
Carotid artery bifurcation
Retrieved from: http://www.aultman.org/ourservices/Additional-AultmanPrograms-andServices/additionalprogramsandservices/AultmanVascularServices/Carotid
ArteryUltrasound.aspx
Internal carotid artery demonstrating obstructing
plague and colour doppler aliasing
Retrieved from: http://www.bobblum.com/ESSAYS/BIOMED/CoronaryCT.html
High resistance common carotid artery
Retrieved from: http://www.angiologist.com/arterial-disease/carotidartery-occlusion/
Vertebral artery
http://sonoscapeportableultrasound.com/wpcontent/uploads/2011/07/Vas.Vertebral-artery.CD_.jpg
Normal vertebral artery
http://www.ultrasoundpaedia.com/uploads/53003/ufiles/vascular/c
arotids/vert-dopp-norm.jpg
References
• Nascet criteria image retrieved from:
http://www.kup.at/journals/abbildungen/
• Normal carotid artery image retrieved from:
http://www.charlesbuntjer.com/chucks_research_projects_20
07_12_14_carotid_arteries.htm
• Carotid artery bifurcation image retrieved
from:http://www.aultman.org/ourservices/AdditionalAultman-Programs-andServices/additionalprogramsandservices/AultmanVascularServ
ices/CarotidArteryUltrasound.aspx
• Internal carotid artery image retrieved
from:http://www.bobblum.com/ESSAYS/BIOMED/CoronaryCT.html
• High resistance common carotid artery image retrieved
from:http://www.angiologist.com/arterial-disease/carotidartery-occlusion/
References
Hamper, M.U., M.R. DeJong, and L.M. Scoutt. 2007. Ultrasound
evaluation of the lower extremity veins. Radiologic Clinics of North
America 45: 525-545.
• Kupinski, A.M. 2013. Diagnostic medical sonography. The
vascular system. Philadelphia: J.K. Stegman3
• Myers, K.A and A. Clough. 2004. Making sense of vascular
ultrasound a hands on guide. London: Arnold
• Zwiebel, W.J., and J. Pellerito. 2005. Introduction to Vascular
Ultrasound. 5th ed. Philadelphia: W.B. Sanders