1. Sonographic Evaluation of Neck Vasculature Cross-Sectional Anatomy
Dr. Harry H. Holdorf
Ph.D., MPA, RDMS (Ab, OB, BR) RVT, LRT(AS)

2. Table of Contents Anatomy Indications for Ultrasound
The Ultrasound examination
2-D
Color Doppler
Spectral Doppler
Diagnostic Criteria

3. Indications for Ultrasound
Evaluation of patients with TIA
Transient Ischemic Attack
Evaluation of patients with CVA
Cerebrovascular Accident
Evaluation of carotid bruits
Follow up of known disease
Monitor endarterectomy results
Evaluation of pulsatile neck mass

4. Carotid Ultrasound Examination
Patient supine
Neck slightly extended
Head slightly turned away from side being scanned
Linear transducer, 5-12 MHz
Protocols vary between operator, institution
B-mode, color Doppler, pulsed Doppler

5. Carotid Ultrasound Examination
B-mode images – Transverse/Sagittal
Images from proximal CCA to bifurcation
Bulb – widening of CCA near bifurcation
Bifurcation – identify and ICA and ECA
Color/Doppler
Proximal/Mid/Distal CCA
Bifurcation (color)
Prox/Mid/Distal ICA
ECA
Vertebral
More images for pathology

6. Anatomy Aortic Arch CCAs lie Innominate or Brachiocephalic artery
Right subclavian artery
Right common carotid
Left common carotid artery
Left subclavian artery
CCAs lie
posterolateral to thyroid
Deep to sternocleidomastoid muscle

8. Anatomy

9. Anatomy Right CCA originates from innominate artery
Left CCA originates from aortic arch
CCAs divide into ECA and ICA
ICA has no branching vessels in the neck; may have slight dilation just past its origin; supplies face and head; lies posterior in the neck
ECA has branching vessels; usually smaller than ICA
Vertebral Arteries – lie between transverse process of the vertebrae

11. Answers to previous slide
Aortic arch angiogram
1. Innominate art.
2. Right subclavian art.
3. Right common carotid art.
4. Right vertebral art.
5. Left common carotid art.
6. Left vertebral art.
7. Left subclavian art.

12. Muscles and Fascia of the Neck

13. Deep dissection of neck
Deep dissection of neck. BIF = bifurcation, SCM= sternocleidomastoid, TM= trapezius muscle

14. Common Carotid Artery

15. Carotid Bifurcation

16. Carotid Bulb with plaque

17. Carotid Bulb with Stent

18. CCA: Anterior Circulation

19. ICA
The internal carotid artery supplies the brain, the eye, the forehead, and part of the nose. It enters the cranial cavity via the carotid canal in the temporal bone.
It gives off no branches within the neck region.
The internal carotid artery supplies perfusion to the anterior and middle portion of the brain, the eye and its appendages and sends branches off to the forehead and nose. It originates at the carotid bifurcation and courses, via a
number of curvatures, through the base of the skull into the Circle of Willis.
The proximal-most portion of this vessel is rather bad bulbous and is referred to as
the bulb. Distal to the bulb, the artery narrows and is referred to as the ICA
proper.
Anatomically, the ICA is distinct from the ECA in that there are no branches until it passes through the base of the skull.
After coursing anteriorly to the transverse processes of the first three cervical vertebrae (C1 –C3), it enters the
carotid canal of the petrous portion of the temporal bone.
The intra-petrous portion of the ICA is also referred to as the cavernous portion of the ICA.
After coursing through the base of the skull, its first branch arises, the ophthalmic
artery, which supplies blood to the retina. (This is of clinical importance when
discussing amaurosis fugax).
At the base of the brain, the ICA gives rise to the
anterior and middle cerebral arteries. The site of this branching is often referred to as the carotid siphon.

21. External Carotid Artery

22. External carotid artery.
Superior thyroidal and lingual artery branches are seen in the submandibular space.
The superficial temporal artery lies anterior to the ear.

23. Vertebral Artery Subclavian Steal
When a stenosis or occlusion of a the proximal subclavian or innominate and the effected side “steals” blood from retrograde vertebral artery flow

24. Vertebral Artery

25. Distinguishing characteristics of the vertebral artery:
First branch off subclavian
Enters foraminal canal at C6
Asymmetrical size: left > right
Low resistance flow

26. Carotid Ultrasound Examination
Differentiate ICA/ECA
ICA is usually lateral
ICA usually larger than ECA
ECA has branches
Temporal tap – tapping of superficial temporal artery in the pre-auricular area; will appear as “saw-teeth” on spectral waveform

27. Carotid Ultrasound Examination Gray Scale Image
Vessel Wall Thickness
IM Complex - .8 mm may be considered abnormal
Plaque Characterization
Homogeneous – smooth surface, uniform echogenicity (p 953)
Calcified – echogenic with posterior shadowing (p 954)
Heterogeneous – complex with at least one sonolucent area corresponding to at least 50% of plaque volume (p 955)
Interplaque hemorrhage – “Swiss cheese” appearance
Plaque ulceration – focal depression/break in surface; or anechoic area that extends to plaque surface; use color/power Doppler (p 952)
Some soft plaque may be very difficult to see on US
Evaluation of Stenosis – % stenosis by diameter/area – taken in transverse plane (p 957)

28. ICA: Duplex characteristics of the ICA. Low resistance waveform
ICA: Duplex characteristics of the ICA. Low resistance waveform. Here a clear spectral window is seen under the spectral envelope.

29. Carotid Ultrasound Examination Color Doppler
Color assignment depends on direction of flow relative to the transducer
Color saturation indicates variable velocities
Lower velocities depicted toward baseline, usually deeper shades
Higher velocities usually brighter shades/colors
Tagging of high velocities
Gain/Scale settings

30. Duplex characteristics of the ECA
Duplex characteristics of the ECA . Rapid systolic upsweep with high resistance flow pattern during diastole. “Temporal tapping” can be seen as spectral oscillations during diastole.

31. Carotid Ultrasound Examination
Altered flow patterns
Pathology
Normal
At area where vessel branches
Where diameter of vessel changes
Tortuosity
High flow jets after stenosis
Low trickle flow

32. Carotid Ultrasound Evaluation Spectral Analysis
Graphic display of velocities and direction of moving red blood cells in the sample volume
X axis, Y axis
Direction of flow
Amplitude of “velocity component” (# of RBCs within each velocity component = brightness of the trace)
Spectral window – black zone between baseline and spectral line

33. CCA Spectral Analysis

35. Carotid Interpretation
Spectral Broadening – occurs when blood cells move with a wider range of velocities; normal spectral window will be filled in
Increases in proportion to the severity of stenosis
Do not confuse with over gain or vessel wall motion
See Rumack p 960 Fig 25-18

36. Carotid Interpretation
Doppler cursor should be in the center of the vessel, parallel to the vessel walls; on high velocity jets
Doppler angles 60 degrees or less
Doppler samples obtained just proximal to, at and just beyond stenosis
1 cm intervals distal to plaque

37. Carotid Ultrasound
ECA – feeds high resistance vascular bed; velocity rises sharply during systole, falls quickly during diastole
ICA – feeds lower resistance brain circulation; large quantities of flow continue during diastole; supplies brain; velocities usually increase from prox to distal
CCA – resembles ICA waveform, with diastolic flow above the baseline

38. Carotid Ultrasound Examination Diagnostic Criteria
Carotid artery stenosis (%)– reduction in diameter
Carotid artery occlusion
No flow detected with color, pulsed Doppler
Thrombus/plaque fills vessel lumen
Reversal of flow proximal to occluded segment
Plaque characterization – as discussed above
Numerical values of some diagnostic criteria may very between institutions
See Rumack p 960

39. Carotid Ultrasound Evaluation Diagnostic Criteria
Degree of stenosis assessed using
ICA pre-systolic velocity
ICA End Diastolic velocity
PS ICA/CCA ratio
PED ICA/CCA ratio
No established criteria for grading ECA stenosis - occlusive plaque in ECA is less common and rarely clinically significant (Rumack)
Velocity criteria used to grade CCA stenosis have not been well established (Rumack)
See Rumack p 967

40. Carotid Ultrasound
> 50 % - mild stenosis; not hemodynamically significant
% moderate stenosis; follow up for progression; hemodynamically significant
70 – 99% - severe stenosis; operable lesion
Occlusion – concern regarding hemodynamic status of intracranial circulation, not an operable lesion
Ulceration – considered clinically significant; can rupture or hemorrhaging; plaque can continue to embolize or occlude ICA

41. Superficial temporal artery:
Terminal branch of ECA.
Supplies skin over frontal and temporal regions of
scalp.
The superior temporal artery, which can be palpated just anterior to the pinna of the ear, is sometimes examined using duplex ultrasound in patients with suspected temporal arteritis.
TEMPORAL TAP METHOD

42. The Superior Temporal Artery

43. Circle of Willis (connecting the two)
Major collateral pathway of brain
Basilar artery formed from fusion of both vertebrals
Internal carotid arteries
Anterior cerebral
Middle cerebral
Basilar artery
Posterior cerebral
Communicating vessels
Anterior communicating artery
(acoa)
Posterior communicating artery
(pcoa)

44. Circle of Willis

45. Posterior Circulation

46. References
Araki, C.T. Introduction to Non-Invasive Vascular Testing. UMDNJ Vascular Technology Program.
Rumack C., Wilson, S. & Carboneau. Diagnostic Ultrasound, 4thEdition, Vol
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Image slide 24 retrieved on November 28, 2012 from