This presentation includes nice carotid doppler and nice explantion for radiology resident. This presentation includes nice doppler images . Thanks

1. Doppler ultrasound of carotid
arteries
Pradeep Kumar

2. Doppler US of carotid arteries
❶ Anatomy of carotid arteries
❷ Normal Doppler US of carotid arteries
❸ Causes of carotid artery disease
❹ Effect of extra-carotid diseases

3. Extracranial cerebral arteries
All arteries that carry blood from heart up to base of skull
Right & left sides of extracranial circulation not symmetrical

4. Variants resulting from elongation of ICA

5. Doppler US of carotid arteries
❶ Anatomy of carotid arteries
❷ Normal Doppler US of carotid arteries
❸ Causes of carotid artery disease
❹ Effect of extra-carotid diseases

6. All carotid artery examinations should be
performed with:
• Gray-scale US
• Color Doppler
• Power Doppler
• Spectral Doppler
Integrate gray scale, color flow, & spectral findings

7. Position for scanning the carotid arteries
Patient lie down in supine or semisupine position
Head hyperextended & rotated 45° away from side being examined
Higher-frequency linear transducers (≥ 7.5 MHz)

8. Doppler ultrasound of carotid arteries / Tips
• Begin each scan on same side, usually the right
• Avoid excess pressure on carotid bifurcation to
avoid
– Stimulate carotid sinus Bradycardia
Syncope
Ventricular asystole
– Compress arteries to cause spurious high
velocities

9. Intima-Media complex
Normal value ≤ 1 mm
Wall of CCA, bulb, or ICA
Best measured on far wall
Only intima & media included

10. Normal carotid bifurcation
Black & white US
ICA Larger & lateral
ECA Smaller & internal
Color Doppler ultrasound

11. Differentiating ICA from ECA

12. Standard Doppler spectral examination
Traces obtained from
• CCA Proximal – Distal
• Carotid Bulb
• ICA Proximal – Middle – Distal
• ECA Proximal
• Vertebral Artery V0 – V1 – V2
• SCA

13. Typical normal Doppler spectra
Common carotid artery
Internal carotid artery
External carotid artery
PSV: 45 – 125 cm/sec
Difference between 2 sides < 15 cm/sec

14. Temporal tap maneuver

15. Temporal tapping of ECA
“Saw-tooth” appearance
Small regular deflections (TT)
Frequency corresponds to rate of temporal tapping

16. Ultrasound of normal vertebral vessels
• Cephalad flow throughout cardiac cycle
• Low resistance flow pattern
• Size: variable & asymmetric – Mean diameter 4 mm
• PSV: 20 – 40 cm/sec – <10 cm/sec potentially abnormal
Vertebral artery
Vertebral vein
• May occasionally be seen adjacent to VA
• Flow caudad & nonpulsatile

17. Normal vertebral artery & vein
Vertebral artery & vein seen between vertebral processes of spine
Color Doppler Pulsed Doppler

18. Doppler US of carotid arteries
❶ Anatomy of carotid arteries
❷ Normal Doppler US of carotid arteries
❸ Causes of carotid artery disease
❹ Effect of extra-carotid diseases

19. Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu
Carotid body tumor
Idiopathic carotidynia
Most common cause

20. Common sites for extracranial arterial disease
Most common site at carotid bifurcation
with plaque extending into ICA

21. Plaque Morphology
Homogenous or Heterogeneous
Can be classified into 4 types on US

22. Appearance of atheromatous plaques
Homogeneous echolucent Homogeneous echogenic
Heterogeneous plaque Cauliflower’ calcification

23. Plaque Ulceration

24. Large plaque ulcer
Power Doppler
“eddy flow”
Color Doppler
Pseudo-dissection

25. Ulcerated plaque or twinkle artifact
Scale 86 cm/sec, color in diastole
Color flow disappeared
Color artifact continues to twinkle
Hard plaque in proximal ICA
Questionable flow at plaque surface

26. Cardinal Doppler parameter to grade stenosis
Best documented Doppler parameter for carotid stenosis
Peak Systolic Velocity (PSV)
Quite valuable for detecting high-grade carotid stenosis
End Diastolic Velocity (EDV)
Avoid errors of collateralization
Avoid errors of physiological factors:
BP – Pulse rate – Cardiac output – Peripheral resistance
PSV ratio

27. Grading of stenosis

28. Relationship between diameter reduction
& cross-sectional area reduction
Diameter reduction
(%)
Cross-sectional area reduction
(%)
30 50
50 75
70 90

29. Criteria for diagnosis of ICA stenosis with
gray scale and Doppler US

30. St. Mary’s Ratio

31. ICA stenosis
PSV 500 cm/sec
EDV 300 cm/sec
Spectral broadening
80% diameter stenosis

32. Color Doppler bruit
Extensive soft tissue color Doppler bruit surrounds
carotid bifurcation with 90% ICA stenosis
Confetti sign

33. Spectral broadening
Immediately after stenosis
High amplitude & low frequency Doppler signal
Poor definition of spectral border
Severe spectral broadening: > 70% diameter reduction

34. Pseudo-spectral broadening
• High gain setting
• Vessel wall motion
• Tortuous vessels
• Site of branching
• Abrupt change in vessel diameter
• ↑ velocity: athlete - high cardiac output - AVF1 - AVM2
• Aneurysm, dissection, & FMD3
1AVF: Arterio-Venous Fistula
2AVM: Arterio-Venous Malformation
3FMD: Fibro-Muscular Dysplasia

35. Post-stenotic zone / Distal to site of stenosis
Tardus-parvus waveform

36. Sonographic features of severe ICA stenosis
❶ Significant visible plaque (≥ 70% diameter reduction)
❷ PSV > 230 cm/sec
❸ EDV > 100 cm/sec
❹ ICA/CCA PSV ratio ≥ 4.0
❺ Spectral broadening
❻ Color aliasing despite high velocity scale (100 cm/sec)
❼ Color bruit artifact in surrounding tissue of stenosis
❽ High-pitched sound at pulsed Doppler

37. Severe stenosis (70%
to near occlusion) of
the ICA.
Duplex US image of the left ICA
shows a high PSV (366 cm/
sec), a significant amount of
visible plaque, the presence of
aliasing despite a high color
scale setting (114 cm/sec),
color flow turbulence
immediately distal to the
stenotic segment, broadening
of the PW Doppler spectrum,
and a high end-diastolic velocity
(182 cm/sec).

38. Tight stenosis or occlusion
• Difficult to distinguish tight stenosis from occlusion
• Completely occluded ICA
Will not release emboli
Not corrected by surgery
• Very severe stenosis
Potential source for emboli or acute thrombosis
May require urgent surgery

39. Optimization of low flow velocities
– Decreased color velocity scale
– Increase color, power & pulsed Doppler gain
– Decreased wall filter
– Focal zone at level of diseased segment
– Doppler angle as low as possible (60° or less)
– Increased persistence
– Increase sample volume gate

40. Subtotal occlusion of ICA
“string sign” or “trickle flow ”
Narrow channel of low-velocity in subtotal ICA occlusion
Low PRF & low filter required to detect low-velocity flow

41. High grade “string sign” stenosis
Tardus-Parvus waveform
Tardus: Long rise time
Parvus: Low PSV

42. Occlusion of ICA
ICA
ECA
CCA
Retrograde flow in stump of ICA
Absence of flow in ICA beyond
Doppler spectrum from CCA
Externalization of CCA

43. Occlusion of ICA
“to-and-fro” flow or thud flow
Damped systolic flow
Reversed flow in early diastole
Pulsed Doppler of CCA

44. Internalization of ECA
Patient with complete occlusion of left ICA

46. Occlusion of CCA
Reversed flow from ECA
to supply ICA & brain
“ECA-to-ICA collateralization”

47. Occlusion of CCA
Absence of flow in distal CCA
Reversed flow in ECA
Normal flow in ICA
Internalization of ECA
Delayed systolic acceleration (tardus)
Positive temporal tap maneuver

48. Schematic Doppler waveforms of VA

49. High-resistance flow in vertebral artery
High-resistance flow
No diastolic component
Distal VA stenosis or occlusion
Hypoplastic vertebral artery
Differential diagnosis:

50. Route of flow in left vertebral steal

51. Types of subclavian steal
Transient reversal of vertebral flow during systole
Converted to partial or complete by provocative maneuver
Pre-steal or bunny waveform
Striking deceleration of velocity in mid or late systole
High-grade stenosis of subclavian rather than occlusion
Incomplete steal
Complete reversal of flow within vertebral artery
Complete steal

52. Vertebral-to-subclavian steal
Presteal
Incomplete steal
Complete steal
Compared to bunny in
profile

53. Provocative maneuver in steal syndrome
Conversion of pre-steal waveform to more pronounced steal
following deflation of pressure cuff
* Inflation of pressure cuff greater than systolic arterial pressure on ipsilateral arm
Inflation of pressure cuff on arm for 3 min & rapid deflation*
Pre-steal More pronounced steal

54. Limitations of carotid US examination
• Short muscular neck
• High carotid bifurcation
• Tortuous vessels
• Calcified shadowing plaques
• Surgical sutures, postoperative hematoma, central line
• Inability to lie flat in respiratory or cardiac disease
• Inability to rotate head in patients with arthritis
• Uncooperative patient

55. Advantages of power mode Doppler
• Angle independent
• No aliasing
• Increases accuracy of grading stenosis
• Distinguish pre-occlusive from occlusive lesions
“detect low-velocity blood flow”
• Superior depiction of plaque surface morphology

56. Disadvantages of power mode Doppler
• Does not provide direction of flow
• Does not provide velocity flow information
• Very motion sensitive (poor temporal resolution)

57. Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibromuscular dysplasia
Dissection
Vasospasm
Aneurysm & pseudoaneurysm
Arterio-venous fistula
Arteritis: Takayasu – Horton
Carotid body tumor
Idiopathic carotidynia
Most common cause

58. Fibromuscular dysplasia
Middle age women – String of beads pattern
Alternating zones of vasoconstriction & vasodilation for 3 – 5 cm
ICA frequently – VA less frequently
Usually bilateral
ICA

59. Arterial Dissection
Intimal rupture with false lumen
Open or secondarily thrombosed
Aorta
External intramural hematoma
Lumen constriction
Rare intimal rupture
Cervical

60. Spontaneous dissection of ICA
Asymmetric wall hematoma – Lumen stenosis – Expansion to outside
Diagnostic criteria (one sufficient)
Intramural hematoma
Intimal rupture/double lumen
Distal stenosis or occlusion
Symptoms: acute pain, Horner,
Course: recanalization in few weeks

61. Dissection of common carotid artery
Transverse view Longitudinal view
Detection of two lumina & dissection membrane

62. Vasospasm
Severe narrowing of ICA No stenosis detected
4 days later

63. Extra-cranial ICA aneurysms
Color Doppler US Power Doppler US
Incomplete delineation of aneurysm – Thrombi could not be excluded

64. Arterio-venous fistula
Attempt to perform US-guided jugular catheter insertion
Turbulent flow in fistula track High-velocity turbulent flow in track
Suspicion of communication between CCA & IJV
CCA
IJV

65. Takayasu’s arteritis
Young female – SCA [‘pulseless’ disease] – CCA
CCA
Long hypoechoic wall thickening
Visualized in color Doppler as dark halo around vascular lumen

66. Horton's arteritis / Giant cell arteritis
Concentric hypoechoic wall thickening
Superficial temporal artery
VA – Longitudinal view VA – Transverse view

67. Doppler US of carotid arteries
❶ Anatomy of carotid arteries
❷ Normal Doppler US of carotid arteries
❸ Causes of carotid artery disease
❹ Effect of extra-carotid diseases

68. Effect of extra-carotid diseases
• Idiopathic dilated cardiomyopathy
• Aortic regurgitation
• Aortic stenosis
• Stenosis of right innominate artery or origin of LCCA
• Stenosis of intra-cranial ICA

69. Idiopathic dilated cardiomyopathy
Pulsus alternans
PSV oscillating between two levels on sequential beats
Cardiac rhythm remains regular throughout

70. Aortic regurgitation
Bisferious waveform [“beat twice” in Latin]
Two systolic peaks separated by midsystolic retraction
Dicrotic notch
Found also with hypertrophic obstructive cardiomyopathy

71. Severe aortic regurgitation
Normal or elevated PSV followed by precipitous decline
Revered flow during diastole
Water-hammer spectral appearance
CCA

72. Right inominate artery stenosis
RICA : to-and-frow flow
RCCA : to-and-frow flow
RVA : reversed flow
RSCA : damped flow
Right carotid steal

73. Thank you

76. CCA DOPPLER STUDY

78. ICA DOPPLER STUDY

86. Questions
• Indications of carotid Doppler study
• Types of plaque.
• Intraplaque hemorrhage.
• Sonographic findings of plaque ulceration
• Advantages of color Doppler study.
• Advantages of power Doppler study.
• Sites for standard Doppler spectral tracings in carotid Doppler study.
• How do you differentiate ICA from ECA
• Normal wave forms of ICA,ECA,CCA
• Features of ICA stenosis
• Features of ICA occlusion
• St. Mary’s ratio
• Doppler spectral wave in subclavian steal