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CAROTID DOPPLER ULTRASOUND
DR. MUHAMMAD BIN ZULFIQAR
PGR 1 FCPS SHL
Part I
Doppler US of carotid arteries
 Anatomy of carotid arteries
 Normal Doppler US of carotid arteries
 Causes of carotid a...
PART I
 Anatomy of carotid arteries
 Normal Doppler US of carotid arteries
 Causes of carotid artery disease
• Common C...
Extra cranial cerebral arteries
All arteries that carry blood from heart up to base of skull
Right & left sides of extra c...
Variants resulting from elongation of ICA
Variations in extracranial circulation
Few
• Left CCA & SCA share single trunk
• Left vertebral artery arising directly fr...
Vertebral artery course
V1
V0
V2
V3
V4
BA
VAs asymmetric in 75 % – Left dominant in 80 %
Posteriorly directed loop when ex...
Doppler US of carotid arteries
 Anatomy of carotid arteries
 Normal Doppler US of carotid arteries
 Causes of carotid a...
All carotid artery examinations should be
performed with:
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
• ...
Position for scanning the carotid arteries
Patient lie down in supine or semisupine position
Head hyperextended & rotated ...
Doppler ultrasound of carotid arteries / Tips
• Begin each scan on same side, usually the right
• Avoid excess pressure on...
Intima-Media complex
Normal value ≤ 0.8 -0.9mm
Wall of CCA, bulb, or ICA
Best measured on far wall
Only intima & media inc...
Normal carotid bifurcation
Gray Scale US
ICA Larger & lateral
ECA Smaller & internal
Normal flow separation
Color Doppler ...
Longitudinal scan to visualize carotid arteries
Anterior
Posterior
Lateral
Carotid bifurcation
Longitudinal B-mode image of carotid bifurcation
ICA & ECA seen in same plane
Normal flow reversal zone in ICA
Velocities highest near flow divider
Flow reversal on opposite side
to flow divider
Flow ...
Internal & external carotid artery
2 small branches originating from ECA
Power Doppler US
Standard Doppler spectral examination
Traces obtained from
• CCA Proximal – Distal
• Carotid Bulb
• ICA Proximal – Middle ...
Typical normal Doppler spectra
Common carotid artery
Internal carotid artery
External carotid artery
Triphasic pattern
Dic...
Dicrotic notch
Normal feature
Closure of aortic valve with temporary cessation of forward flow
Resumption of forward flow ...
Coiling of ICA
Congenital - Bilateral - Symmetrical
Abnormal Doppler flow in tortuous vessel
Tortuous CCA displays color
Doppler eccentric jets of flow
High velocity due to e...
Temporal tapping of ECA
“Saw-tooth” appearance
Small regular deflections (TT)
Frequency corresponds to rate of temporal ta...
Differentiation between ICA & ECA
Features ICA ECA
 Size Usually larger Usually smaller
 Temporal tap Usually negative U...
Protocol for VA examination
– Direction of flow
– Waveform configuration
– Measure PSV
Longitudinal VA between transverse ...
Ultrasound of normal vertebral vessels
Cephalad flow throughout cardiac cycle
Low resistance flow pattern
VA origin regula...
Normal vertebral artery origin
V0
Normal vertebral artery & vein
V2
Vertebral artery & vein seen between vertebral processes of spine
Color Doppler Pulsed D...
Subclavian artery
Mirror image below
pleura
Color Doppler US Pulsed Doppler US
Normal triphasic waveform
Doppler US of carotid arteries
 Anatomy of carotid arteries
 Normal Doppler US of carotid arteries
 Causes of carotid a...
Causes of carotid artery diseases
Arteriosclerotic disease
Non-arteriosclerotic diseases
Fibro muscular dysplasia
Dissecti...
Extracranial carotid artery & stroke
• Stroke is third leading cause of death in USA
• > 500,000 new cases of CVA reported...
Common sites for extracranial arterial disease
Most common site at carotid bifurcation
with plaque extending into ICA
Plaque characterization
Low Lipid – Flow void
Moderate Collagen – Easy to see
High with shadow Calcification – Focal or di...
Appearance of atheromatous plaques
Homogeneous echolucent Homogeneous echogenic
Heterogeneous plaque Cauliflower’ calcific...
Calcified plaque
Calcific plaque with shadow
obscuring portion of the bulb
Interrogate artery beyond plaque
Shadowing segm...
Intraplaque hemorrhage
Sources of error in ulcer diagnosis
Plaque surface irregular
but not ulcerated
Adjacent plaque
simulate ulceration
Image p...
Large plaque ulcer
Power Doppler
“eddy flow”
Color Doppler
Pseudo-dissection
Ulcerated plaque or twinkle artifact
Scale 86 cm/sec, color in diastole
Color flow disappeared
Color artifact continues to...
Estimation of carotid stenosis
Diameter reduction Surface reduction
Relationship between diameter reduction
& cross-sectional area reduction
Diameter reduction
(%)
Cross-sectional area reduc...
Cardinal Doppler parameter to grade stenosis
Best documented Doppler parameter for carotid stenosis
Peak Systolic Velocity...
Relationship of flow, velocity & lumen size
Spencer MP & Reid JM. Stroke 1979 ; 10 : 326 – 330.
Grading stenosis – PSV ratio
Proximal: 2 cm proximal to carotid bulb
At stenosis: same Doppler angle if possible
Normal va...
17 authors:
1 Moderator
16 panelists
San Francisco, Calif
October 22–23, 2002
ICA stenosis on angiogram
ECST 2 (1998)
European Carotid Surgery Trial
(C – A / C) x 100
NASCET 1 (1991 – 1998)
North Amer...
ICA stenosis on angiogram
Diameter reduction
* NASCET: North American Symptomatic Carotid Endartectomy Trial
** ECST: Euro...
Degree of ICA Stenosis in Doppler US*
Consensus Criteria – NASCET criteria
ICA stenosis ICA PSV ICA EDV PSV ratio
(%) cm/s...
Degree of ICA Stenosis in Doppler US*
Consensus Criteria – NASCET criteria
ICA stenosis ICA PSV ICA EDV PSV ratio
(%) cm/s...
Aliasing or high velocity jet
Area of highest velocity in area of stenosis
Adjustment of color gain
Color gain at 80%
Marked turbulence of ICA & ECA
No luminal narrowing
Anatomy of bifurcation
demo...
ICA stenosis
PSV 500 cm/sec
EDV 300 cm/sec
Spectral broadening
80% diameter stenosis
Color Doppler bruit
Extensive soft tissue color Doppler bruit surrounds
carotid bifurcation with 90% ICA stenosis
Confetti...
Post stenotic zone/ Immediately after stenosis
• Cannot be precisely quantified (evaluated visually)
Fill-in of spectral w...
Spectral broadening
Immediately after stenosis
High amplitude & low frequency Doppler signal
Poor definition of spectral b...
Pseudo-spectral broadening
• High gain setting
• Vessel wall motion
• Tortuous vessels
• Site of branching
• Abrupt change...
Post stenotic zone / Distal to site of stenosis
Tardus-parvus waveform
Sonographic features of severe ICA stenosis
 Significant visible plaque (≥ 70% diameter reduction)
 PSV > 230 cm/sec
 E...
Tight stenosis or occlusion?
• Difficult to distinguish tight stenosis from occlusion
• Completely occluded ICA
Will not r...
Optimization of low flow velocities
• Decreased color velocity scale
• Increase color, power & pulsed Doppler gain
• Decre...
Subtotal occlusion of ICA
“string sign” or “trickle flow ”
Narrow channel of low-velocity in subtotal ICA occlusion
Low PR...
High grade “string sign” stenosis
Tardus Parvus waveform
Tardus: Long rise time
Parvus: Low PSV
Endarterectomy without arteriography
• Arteriography Expensive
Risks: stroke (0.1 – 0.6%) – death (0.1%)
Rarely affect sur...
Causes of image/Doppler mismatch
• Cardiac arrhythmia
• Severe aortic stenosis
• Hypotension or hypertension
• Tortuous ve...
Short & long stenosis of ICA
Short stenosis (frequent) Long stenosis (rare)
PSV lower than expected
EDV maintained at high...
Long stenosis of ICA
Zwiebel WJ et al. Ultrasound Quarterly 2005 ; 21 : 113 – 122.
RICA
RICA: PSV 183 cm/sec
EDV 105 cm/se...
Occlusion of ICA
• Absence of flow by color, power & pulsed Doppler
• “Internalization” of ipsilateral ECA waveform
• Reve...
Occlusion of ICA
ICA
ECA
CCA
Retrograde flow in stump of ICA
Absence of flow in ICA beyond
Doppler spectrum from CCA
Exter...
Occlusion of ICA
“to-and-fro” flow or thud flow
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Damped systo...
Internalization of ECA
Patient with complete occlusion of left ICA
Occlusion of CCA
Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.
Reversed flow from ECA
to supply ICA & brain
“ECA-...
Occlusion of CCA
Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
Absence of flow in distal CCA
Reversed flow...
Stenosis of ECA
• PSV of ECA stenosis Minimal < 200 cm/sec
Moderate 200 – 300 cm/sec
Severe > 300 cm/sec
• ECA/CCA systoli...
Ectatic CCA
Ectatic CCA as it arises from innominate artery
Responsible for pulsatile right supra clavicular mass
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New carotid doppler ultrasound

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New carotid doppler ultrasound

  1. 1. CAROTID DOPPLER ULTRASOUND DR. MUHAMMAD BIN ZULFIQAR PGR 1 FCPS SHL Part I
  2. 2. Doppler US of carotid arteries  Anatomy of carotid arteries  Normal Doppler US of carotid arteries  Causes of carotid artery disease  Effect of extra-carotid diseases
  3. 3. PART I  Anatomy of carotid arteries  Normal Doppler US of carotid arteries  Causes of carotid artery disease • Common Carotid Artery • Internal Carotid Artery • External carotid Artery
  4. 4. Extra cranial cerebral arteries All arteries that carry blood from heart up to base of skull Right & left sides of extra cranial circulation not symmetrical
  5. 5. Variants resulting from elongation of ICA
  6. 6. Variations in extracranial circulation Few • Left CCA & SCA share single trunk • Left vertebral artery arising directly from aortic arch • Right vertebral origin arising directly from aortic arch
  7. 7. Vertebral artery course V1 V0 V2 V3 V4 BA VAs asymmetric in 75 % – Left dominant in 80 % Posteriorly directed loop when exists C1 transverse process 2 VAs units to form basilar artery: collateralization
  8. 8. Doppler US of carotid arteries  Anatomy of carotid arteries  Normal Doppler US of carotid arteries  Causes of carotid artery disease  Effect of extra-carotid diseases
  9. 9. All carotid artery examinations should be performed with: Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. • Gray-scale US • Color Doppler • Power Doppler • Spectral Doppler Integrate gray scale, color flow, & spectral findings
  10. 10. 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)
  11. 11. 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
  12. 12. Intima-Media complex Normal value ≤ 0.8 -0.9mm Wall of CCA, bulb, or ICA Best measured on far wall Only intima & media included
  13. 13. Normal carotid bifurcation Gray Scale US ICA Larger & lateral ECA Smaller & internal Normal flow separation Color Doppler ultrasound
  14. 14. Longitudinal scan to visualize carotid arteries Anterior Posterior Lateral
  15. 15. Carotid bifurcation Longitudinal B-mode image of carotid bifurcation ICA & ECA seen in same plane
  16. 16. Normal flow reversal zone in ICA Velocities highest near flow divider Flow reversal on opposite side to flow divider Flow reversal zone Opposite to origin of ECA
  17. 17. Internal & external carotid artery 2 small branches originating from ECA Power Doppler US
  18. 18. Standard Doppler spectral examination Traces obtained from • CCA Proximal – Distal • Carotid Bulb • ICA Proximal – Middle – Distal • ECA Proximal • Vertebral Artery V0 – V1 – V2 • SCA
  19. 19. Typical normal Doppler spectra Common carotid artery Internal carotid artery External carotid artery Triphasic pattern Dicrotic notch PSV: 45 – 125 cm/sec Difference between 2 sides < 15 cm/sec
  20. 20. Dicrotic notch Normal feature Closure of aortic valve with temporary cessation of forward flow Resumption of forward flow by elastic rebound of aortic wall
  21. 21. Coiling of ICA Congenital - Bilateral - Symmetrical
  22. 22. Abnormal Doppler flow in tortuous vessel Tortuous CCA displays color Doppler eccentric jets of flow High velocity due to eccentric jet in tortuous CCA Tortuosity can increase velocity, although there is no stenosis Try sampling just beyond the curve
  23. 23. Temporal tapping of ECA “Saw-tooth” appearance Small regular deflections (TT) Frequency corresponds to rate of temporal tapping Deflections best seen during diastole
  24. 24. Differentiation between ICA & ECA Features ICA ECA  Size Usually larger Usually smaller  Temporal tap Usually negative Usually positive  Pulsed Doppler Low resistance High resistance  Orientation Posterior Anterior  Branches Rarely Yes
  25. 25. Protocol for VA examination – Direction of flow – Waveform configuration – Measure PSV Longitudinal VA between transverse processes Caudad survey – Follow artery cauded to its origin Cephalad survey – Follow artery cephalad above transverse processes
  26. 26. Ultrasound of normal vertebral vessels Cephalad flow throughout cardiac cycle Low resistance flow pattern VA origin regularly seen by experienced sonographers 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
  27. 27. Normal vertebral artery origin V0
  28. 28. Normal vertebral artery & vein V2 Vertebral artery & vein seen between vertebral processes of spine Color Doppler Pulsed Doppler
  29. 29. Subclavian artery Mirror image below pleura Color Doppler US Pulsed Doppler US Normal triphasic waveform
  30. 30. Doppler US of carotid arteries  Anatomy of carotid arteries  Normal Doppler US of carotid arteries  Causes of carotid artery disease  Effect of extra-carotid diseases
  31. 31. Causes of carotid artery diseases Arteriosclerotic disease Non-arteriosclerotic diseases Fibro muscular dysplasia Dissection Vasospasm Aneurysm & pseudo aneurysm Arterio-venous fistula Arteritis: Takayasu – Horton Carotid body tumor Idiopathic carotidynia Most common cause
  32. 32. Extracranial carotid artery & stroke • Stroke is third leading cause of death in USA • > 500,000 new cases of CVA reported annually • 20 – 30% of stokes due to severe carotid artery stenosis • Stenosis involves ICA within 2 cm of bifurcation • CEA* more beneficial than medical tm in symptomatic or asymptomatic patients with > 70% carotid stenosis** * CEA: Carotid endarterectomy ** NASCET: North American Symptomatic Carotid Endartectomy Trial ** ECST: European Carotid Surgery Trial
  33. 33. Common sites for extracranial arterial disease Most common site at carotid bifurcation with plaque extending into ICA
  34. 34. Plaque characterization Low Lipid – Flow void Moderate Collagen – Easy to see High with shadow Calcification – Focal or diffuse  Echogenicity Calcification: no correlation with neurologic symptoms Focal hypoechoic zones: Hemorrhage – Necrosis – Lipid  Heterogenous plaque Common sources of cerebral emboli: TIA – Stroke Poor US results for ulcer detection  Plaque surface features
  35. 35. Appearance of atheromatous plaques Homogeneous echolucent Homogeneous echogenic Heterogeneous plaque Cauliflower’ calcification
  36. 36. Calcified plaque Calcific plaque with shadow obscuring portion of the bulb Interrogate artery beyond plaque Shadowing segment < 1 cm No turbulent flow: insignificant stenosis Damped or turbulent flow: tight stenosis Shadowing segment > 2 cm Degree of stenosis indeterminate Other modalities recommended
  37. 37. Intraplaque hemorrhage
  38. 38. Sources of error in ulcer diagnosis Plaque surface irregular but not ulcerated Adjacent plaque simulate ulceration Image plan does not include the ulcer
  39. 39. Large plaque ulcer Power Doppler “eddy flow” Color Doppler Pseudo-dissection
  40. 40. 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
  41. 41. Estimation of carotid stenosis Diameter reduction Surface reduction
  42. 42. Relationship between diameter reduction & cross-sectional area reduction Diameter reduction (%) Cross-sectional area reduction (%) 30 50 50 75 70 90
  43. 43. 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
  44. 44. Relationship of flow, velocity & lumen size Spencer MP & Reid JM. Stroke 1979 ; 10 : 326 – 330.
  45. 45. Grading stenosis – PSV ratio Proximal: 2 cm proximal to carotid bulb At stenosis: same Doppler angle if possible Normal value < 2.0
  46. 46. 17 authors: 1 Moderator 16 panelists San Francisco, Calif October 22–23, 2002
  47. 47. ICA stenosis on angiogram ECST 2 (1998) European Carotid Surgery Trial (C – A / C) x 100 NASCET 1 (1991 – 1998) North American Symptomatic Carotid Endartectomy Trial (B – A / B) x 100
  48. 48. ICA stenosis on angiogram Diameter reduction * NASCET: North American Symptomatic Carotid Endartectomy Trial ** ECST: European Carotid Surgery Trial 30% 65% 40% 70% 50% 75% 60% 80% 70% 85% 80% 91% 90% 97% * NASCET (B – A / B) x 100 ** ECST (C – A / C) x 100
  49. 49. Degree of ICA Stenosis in Doppler US* Consensus Criteria – NASCET criteria ICA stenosis ICA PSV ICA EDV PSV ratio (%) cm/sec cm/sec ICA/CCA Normal < 125 < 40 < 2.0 < 50% < 125 < 40 < 2.0 50 – 69% 125 – 230 40 – 100 2.0 – 4.0 > 70% > 230 > 100 > 4.0 Near occlusion variable variable variable Total occlusion undetectable undetectable not applicable
  50. 50. Degree of ICA Stenosis in Doppler US* Consensus Criteria – NASCET criteria ICA stenosis ICA PSV ICA EDV PSV ratio (%) cm/sec cm/sec ICA/CCA Normal < 125 < 40 < 2.0 < 50% < 125 < 40 < 2.0 50 – 69% 125 – 230 40 – 100 2.0 – 4.0 > 70% > 230 > 100 > 4.0 Near occlusion variable variable variable Total occlusion undetectable undetectable not applicable
  51. 51. Aliasing or high velocity jet Area of highest velocity in area of stenosis
  52. 52. Adjustment of color gain Color gain at 80% Marked turbulence of ICA & ECA No luminal narrowing Anatomy of bifurcation demonstrated more accurately Color gain at 66%
  53. 53. ICA stenosis PSV 500 cm/sec EDV 300 cm/sec Spectral broadening 80% diameter stenosis
  54. 54. Color Doppler bruit Extensive soft tissue color Doppler bruit surrounds carotid bifurcation with 90% ICA stenosis Confetti sign
  55. 55. Post stenotic zone/ Immediately after stenosis • Cannot be precisely quantified (evaluated visually) Fill-in of spectral window > 50% diameter reduction Severely disturbed flow > 70% diameter reduction High amplitude & low frequency Doppler signal Flow reversal Poor definition of spectral border • May be only sign of carotid stenosis in calcified plaque Spectral broadening
  56. 56. Spectral broadening Immediately after stenosis High amplitude & low frequency Doppler signal Poor definition of spectral border Flow reversal Severe spectral broadening: > 70% diameter reduction
  57. 57. 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
  58. 58. Post stenotic zone / Distal to site of stenosis Tardus-parvus waveform
  59. 59. Sonographic features of severe ICA stenosis  Significant visible plaque (≥ 70% diameter reduction)  PSV > 230 cm/sec  EDV > 100 cm/sec  ICA/CCA PSV ratio ≥ 4.0  Spectral broadening  Color aliasing despite high velocity scale (100 cm/sec)  Color bruit artifact in surrounding tissue of stenosis  High-pitched sound at pulsed Doppler
  60. 60. 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
  61. 61. 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
  62. 62. 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
  63. 63. High grade “string sign” stenosis Tardus Parvus waveform Tardus: Long rise time Parvus: Low PSV
  64. 64. Endarterectomy without arteriography • Arteriography Expensive Risks: stroke (0.1 – 0.6%) – death (0.1%) Rarely affect surgical plan Sufficient information obtained with MRI • Conditions Good experience of US department Stenosis localized to carotid bifurcation Unequivocal US findings Symptoms ipsilateral to carotid stenosis
  65. 65. Causes of image/Doppler mismatch • Cardiac arrhythmia • Severe aortic stenosis • Hypotension or hypertension • Tortuous vessels • Hypoechoic, anechoic or calcified plaques • Long segment high grade stenosis • Pre-occlusive lesion • Tandem lesion • Contra-lateral carotid stenosis • Carotid dissection
  66. 66. Short & long stenosis of ICA Short stenosis (frequent) Long stenosis (rare) PSV lower than expected EDV maintained at high level Can produce very high PSV (> 500 cm/s)
  67. 67. Long stenosis of ICA Zwiebel WJ et al. Ultrasound Quarterly 2005 ; 21 : 113 – 122. RICA RICA: PSV 183 cm/sec EDV 105 cm/sec CCA: PSV 76 cm/sec PSV ratio: 2.4 Inconsistent data Long stenosis of ICA > 70%
  68. 68. Occlusion of ICA • Absence of flow by color, power & pulsed Doppler • “Internalization” of ipsilateral ECA waveform • Reversed flow in ICA or CCA proximal to occlusion • Thrombus or plaque completely fills lumen of ICA • Externalization of ipsilateral CCA or proximal ICA • Higher velocities in contralateral CCA vs. ipsilateral CCA
  69. 69. 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
  70. 70. Occlusion of ICA “to-and-fro” flow or thud flow Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. Damped systolic flow Reversed flow in early diastole Pulsed Doppler of CCA
  71. 71. Internalization of ECA Patient with complete occlusion of left ICA
  72. 72. Occlusion of CCA Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131. Reversed flow from ECA to supply ICA & brain “ECA-to-ICA collateralization”
  73. 73. Occlusion of CCA Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. 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
  74. 74. Stenosis of ECA • PSV of ECA stenosis Minimal < 200 cm/sec Moderate 200 – 300 cm/sec Severe > 300 cm/sec • ECA/CCA systolic ratio* < 2 ≤ 50% Ø stenosis ≥ 2 ≥ 70% Ø stenosis Isolated ECA stenosis not clinically significant
  75. 75. Ectatic CCA Ectatic CCA as it arises from innominate artery Responsible for pulsatile right supra clavicular mass
  76. 76. Thank You

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