Doppler ultrasound of carotid arteries

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  • CCA, which has no branches, divides into the internal and external carotid arteries.Carotid artery widens at the level of the bifurcation to form the carotid bulb & degree of widening of carotid bulb is quite variable.Level of the carotid bifurcation in the neck is highly variable.Proximal branches of the ECA are the superior thyroid, lingual, facial and maxillary arteries.Vertebral artery is the first branch of the subclavian artery, arising from the highest point of the subclavian arch. At the sixth cervical vertebra, the vertebral artery runs posteriorly to travel upward through the transverse foramen of cervical vertebrae.Two vertebral arteries join, at the base of the skull, to form basilar artery, which then divides to form posterior cerebral arteries.
  • Tortuosity can cause apparent velocity increase even although there is no stenosis. This is due to difficulty in obtaining a correct insonating angle, non-linear or helical flow, or increased velocityon the inside of the curve. Try sampling just beyond the curve.
  • “Saw-tooth” appearance: مظهر أسنان المنشار
  • Endarterectomy decrease the risk of ipsi-lateral hemispheric stroke or death by 53 to 84% as compared to medical treatment.
  • Cauliflower: قرنبيط
  • Eddy: دوامة
  • A panel of experts from a variety of medical specialties was convened under the auspices of the Society of Radiologists in Ultrasound to arrive at a consensus about the performance of Doppler ultrasonography (US) to aid in diagnosis of internal carotid artery (ICA)stenosis. The panel met in San Francisco, Calif, October 22–23, 2002, and drew up a consensus statement. Although there are several facets of carotid disease that could be considered by such a panel, carotid stenosis(and by extension, carotid occlusion) is by far the most common pathologic process involving carotid arteries.The panel consisted of a moderator and 16 panelists from various medical specialties.
  • the method used to report the degree of narrowing from an angiogram differed between the European and North American trials.In the ECST trial, the degree of stenosis was measured by comparing the residual lumen diameter with the estimated diameter of the carotid bulb, whereas the NASCET trial compared the residual lumen diameter with the diameter of the normal distal ICA.
  • In the North American Symptomatic Carotid Endartectomy Trial, the narrowest portion of the vascular lumen was compared with the “normalized lumen distally”.In the European Symptomatic Carotid Trial study and studies performed prior to the NASCET study, the degree of stenosis was determined by comparing the narrowest diameter of the residual lumen to an estimate of the original lumen in the same area. Because the original lumen cannot be depicted on the angiogram, exact measurement is impossible.The panel recommended that the NASCET method of carotid stenosis measurement should be employed when angiography is used to correlate the US findings. While the NASCET method of measurement may not reflect the burden of atherosclerosis in the proximal ICA, it does minimize the amount of interobserver variability.
  • string sign” stenosis: علامة الخيط أو الحبل أو السلك
  • Long stenosis: > 2 cm
  • It can be difficult to distinguish tight stenosis from occlusion. A completely occluded ICA cannot be corrected by surgery and will not release emboli. However, very severe stenosis can be a potential source for emboli or acute thrombosis and may require urgent surgery.
  • Thud: صوت مكتوم
  • The ECA is an important collateral pathway in patients with ipsilateral ICA occlusion and recurrent symptoms.This may influence the surgical decisions involving revascularization of the stenotic ECA.
  • Differentiation between these causes is important, as some centers are performing vertebral artery angioplasty and stent placement for significant vertebral artery stenosis.
  • Wall hematoma: Wall hematoma might be incorrectly interpreted as arteritis.However, an important differentiation criterion is the eccentric location of the wall thickening in the case of dissection as known from MRI findings, while vasculitis is characterized by concentric wall thickening.Double lumen:If double are detected, a pathological Doppler curve (showing stenosis or oscillating flow) will be found in at least one of the lumina. Therefore, fenestration of the VA (an anomaly with a double lumen in one vessel segment) cannot be confused with dissection becauseof the normal flow pulse curve in both lumina.Horner:
  • If 2 lumina are detected, a pathological Doppler curve (showing stenosis or oscillating flow) will be found in at least one of the lumina. Therefore, fenestration of the VA (an anomaly with a double lumen in one vessel segment) cannot be confused with dissection because of the normal flow pulse curve in both lumina.
  • True aneurysm generally defined as dilation of an artery to more than 150% of its normal diameterDifficult definition for extracranial carotid artery aneurysms due to normal dilatation of bulbDe Jong et al. proposed that ECAA of the bifurcation are better defined as a bulb dilatation greater than 200% of the diameter of the ICA or 150% of the diameter of the common carotid artery, and distal aneurysms of the extracranial internal carotid arteries (EICAA) as a dilatation greater than 120% of the diameter of the normal ipsilateral ICA.
  • Temporal (giant cell) arteritis affects the superficial temporal arteries in older women.The specificity of the method under qualified application is 97%. Therefore, given a clear vasculitis finding in the ultrasound image and an experienced examiner, a vascular biopsy can be dispensed with.In the case of unclear ultrasound findings or ultrasound findings without pathological findings and a clinical suspicion of arteritis, biopsy is still necessary.
  • Each diamond corresponds to a study estimate of sensitivity and specificity.Area of each diamond is proportional to the study sizeThe upper and lower curves represent the 95 per cent confidence intervals of the diagnostic odds ratio in the equation of curve.The presence of any of the markers of vascular inflammation (halo, stenosis, occlusion), compared with halo alone, seemed to improve sensitivity, while retaining specificity, although there was significant between-study heterogeneity (I2 = 81·7 per cent, P < 0·001).
  • “carotidynia” was initially described by Fay in 1927.Clinical criteria for dg of idiopathic carotidynia were established in 1988 by International Headache Society Classification Committee.The existence of this entity remained controversial and led the International Headache Society to remove carotidynia from their main classification of Headache Disorders in 2004.Severe pain on one side in the upper cervical region that responds well to cortisone or NSAIDs.
  • Pulsus alternans: نبض متناوبPatient with pulsus alternans caused by idiopathic dilated cardiomyopathy.
  • Pulsusbisferiens, Latin for ‘‘beat twice,’’ is the term used to describe a waveform characterized by two systolic peaks with an interposed midsystolic retraction. Visualization of this waveform suggests the presence of aortic insufficiency with or without concomitant aortic stenosis or hypertophicobstructive cardiomyopathy.Mechanism of pulsusbisferiens in aortic insufficiency is not well understood. One view is that first peak represents initial high-volume ejection of blood, which is followed by abrupt mid systolic flow deceleration caused by regurgitant valve, and second peak represents tidal wave reflected from distended aorta as it relaxes or from periphery of body.
  • Water Hammer: الطرق المائي (صوت طرق الماء على جوانب الأنبوب الذي يحتويه)Hammer: مطرقةSpectral waveforms mirror physical examination finding of water-hammer pulses in patients with severe aortic regurgitation.
  • Reduced right arm systolic blood pressure. A right-to-left difference of 20 mm Hg is considered significant.
  • Doppler ultrasound of carotid arteries

    1. 1. Doppler ultrasound of carotid arteries Samir Haffar M.D. Assistant Professor of internal medicine
    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. Extracranial cerebral arteries All arteries that carry blood from heart up to base of skull Right & left sides of extracranial circulation not symmetrical
    4. 4. Variants resulting from elongation of ICA
    5. 5. 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 Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005.
    6. 6. Vertebral artery course V1 V0 V2 V3 V4 BA VAs asymetric in 75 % – Left dominant in 80 % Posteriorly directed loop when exists C1 transverse process 2 VAs units to form basilar artery: collateralization
    7. 7. 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
    8. 8. 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
    9. 9. Position for scanning the carotid arteries Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005. Patient lie down in supine or semisupine position Head hyperextended & rotated 45° away from side being examined Higher-frequency linear transducers (≥ 7.5 MHz)
    10. 10. 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 Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
    11. 11. Intima-Media complex Normal value ≤ 0.8 mm Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004. Wall of CCA, bulb, or ICA Best measured on far wall Only intima & media included
    12. 12. Normal carotid bifurcation Black & white US ICA Larger & lateral ECA Smaller & internal Normal flow separation Color Doppler ultrasound
    13. 13. Longitudinal scan to visualize carotid arteries Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005. Anterior Posterior Lateral
    14. 14. Carotid bifurcation Longitudinal B-mode image of carotid bifurcation ICA & ECA seen in same plane Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005.
    15. 15. 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
    16. 16. Internal & external carotid artery Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005. 2 small branches originating from ECA Power Doppler US
    17. 17. Standard Doppler spectral examination Traces obtained from • CCA Proximal – Distal • Carotid Bulb • ICA Proximal – Middle – Distal • ECA Proximal • Vertebral Artery V0 – V1 – V2 • SCA
    18. 18. Typical normal Doppler spectra Common carotid artery Internal carotid artery External carotid artery Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000. PSV: 45 – 125 cm/sec Difference between 2 sides < 15 cm/sec
    19. 19. Dicrotic notch Normal feature Ginat DT et al. Ultrasound Quarterly 2011 ; 27 : 81 – 85. Closure of aortic valve with temporary cessation of forward flow Resumption of forward flow by elastic rebound of aortic wall
    20. 20. Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. Coiling of ICA Congenital - Bilateral - Symmetrical
    21. 21. 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
    22. 22. Temporal tap maneuver
    23. 23. Abropoulos NL et al. Vasc Endovascular Surg 2007 ; 41 : 417 – 427. 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. Temporal tap Internal & external carotid artery findings ICA temporal tap ECA temporal tap Normal + / − + Significant ICA stenosis − + Significant ECA stenosis + − Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131. Not proved reliable
    25. 25. 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
    26. 26. Protocol for VA examination – Direction of flow – Waveform configuration – Measure PSV Longitudinal VA between transverse processes Cauded survey – Follow artery cauded to its origin Cephalad survey – Follow artery cephalad above transverse processes
    27. 27. 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
    28. 28. Normal vertebral artery origin V0 Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    29. 29. Normal vertebral artery & vein V2 Vertebral artery & vein seen between vertebral processes of spine Color Doppler Pulsed Doppler Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    30. 30. Subclavian artery Mirror image below pleura Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005. Color Doppler US Pulsed Doppler US Normal triphasic waveform
    31. 31. 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
    32. 32. 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
    33. 33. 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 benefical than medical tt in symptomatic or asymptomatic patients with > 70% carotid stenosis** * CEA: Carotid endarterectomy ** NASCET: North American Symptomatic Carotid Endartectomy Trial ** ECST: European Carotid Surgery Trial
    34. 34. Common sites for extracranial arterial disease Most common site at carotid bifurcation with plaque extending into ICA Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004.
    35. 35. Plaque characterization Low Lipid – < SCM – Flow void Moderate Collagen – Easy to see – > SCM 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
    36. 36. Appearance of atheromatous plaques Homogeneous echolucent Homogeneous echogenic Myers KA & Clough A. Making sense of vascular ultrasound. Arnold, London, 2004. Heterogeneous plaque Cauliflower’ calcification
    37. 37. Calcified plaque Calcific plaque with shadow obscuring portion of the bulb Interrogate artery beyond plaque Shadowing segment < 1 cm No turbulent flow: unsignificant stenosis Damped or turbulent flow: tight stenosis Shadowing segment > 2 cm Degree of stenosis indeterminate Other modalities recommended
    38. 38. Intraplaque hemorrhage Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
    39. 39. Sources of error in ulcer diagnosis Plaque surface irregular but not ulcerated Adjacent plaque simulate ulceration Image plan does not include the ulcer Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    40. 40. Large plaque ulcer Power Doppler “eddy flow” Color Doppler Pseudo-dissection Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    41. 41. Ulcerated plaque or twinkle artifact Scale 86 cm/sec, color in diastole Color flow disappeared Color artifact continues to twinkle Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. Hard plaque in proximal ICA Questionable flow at plaque surface
    42. 42. Estimation of carotid stenosis Diameter reduction Surface reduction
    43. 43. Relationship between diameter reduction & cross-sectional area reduction Diameter reduction (%) Cross-sectional area reduction (%) 30 50 50 75 70 90
    44. 44. 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
    45. 45. Relationship of flow, velocity & lumen size Spencer MP & Reid JM. Stroke 1979 ; 10 : 326 – 330.
    46. 46. Grading stenosis – PSV ratio Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131. Proximal: 2 cm proximal to carotid bulb At stenosis: same Doppler angle if possible Normal value < 2.0
    47. 47. Grant EG et al. Radiology 2003 ; 229 : 340 – 346. 17 authors: 1 Moderator 16 panelists San Francisco, Calif October 22–23, 2002
    48. 48. PSV, EDV & PSV ratio & degree of ICA stenosis NASCET criteria Grant EG et al. Radiology 2000 ; 214 : 247 – 252. PSV & EDV ICA /CCA PSV
    49. 49. 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 1 NASCET. N Engl J Med 1991 ; 325 : 445 – 453.
    50. 50. 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
    51. 51. 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 * Diameter reduction Grant EG et al. Radiology 2003 ; 229 : 340 – 346.
    52. 52. 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 * Diameter reduction Grant EG et al. Radiology 2003 ; 229 : 340 – 346.
    53. 53. Aliasing or high velocity jet Area of highest velocity in area of stenosis
    54. 54. Adjustment of color gain Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. Color gain at 80% Marked turbulence of ICA & ECA No luminal narrowing Anatomy of bifurcation demonstrated more accurately Color gain at 66%
    55. 55. ICA stenosis PSV 500 cm/sec EDV 300 cm/sec Spectral broadening 80% diameter stenosis
    56. 56. Color Doppler bruit Extensive soft tissue color Doppler bruit surrounds carotid bifurcation with 90% ICA stenosis Confetti sign
    57. 57. 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
    58. 58. Spectral broadening Immediately after stenosis High amplitude & low frequency Doppler signal Poor definition of spectral border Flow reversal Severe spectral broadening: > 70% diameter reduction
    59. 59. 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
    60. 60. Post-stenotic zone / Distal to site of stenosis Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704. Tardus-parvus waveform
    61. 61. 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 Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
    62. 62. 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
    63. 63. 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
    64. 64. 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
    65. 65. High grade “string sign” stenosis Tardus-Parvus waveform Tardus: Long rise time Parvus: Low PSV
    66. 66. Endarterctomy 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 Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    67. 67. 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 • Contro-lateral carotid stenosis • Carotid dissection
    68. 68. Short & long stenosis of ICA Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131. Zwiebel WJ et al. Ultrasound Quarterly 2005 ; 21 : 113 – 122. Short stenosis (frequent) Long stenosis (rare) PSV lower than expected EDV maintained at high level Can produce very high PSV (> 500 cm/s)
    69. 69. 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%
    70. 70. 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 controlateral CCA vs ipsilateral CCA
    71. 71. 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
    72. 72. 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
    73. 73. Internalization of ECA Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704. Patient with complete occlusion of left ICA
    74. 74. Stenosis of ECA • PSV of ECA stenosis Minimal < 200 cm/sec “Guesstimate” Moderate 200 – 300 cm/sec Severe > 300 cm/sec • ECA/CCA systolic ratio* < 2 ≤ 50% Ø stenosis ≥ 2 ≥ 70% Ø stenosis * Päivänsalo MJ et al. Acta Radiologica 1996 ; 37 : 41 – 43. Isolated ECA stenosis not clinically significant
    75. 75. 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”
    76. 76. 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
    77. 77. Ectatic CCA Ectatic CCA as it arises from inominate artery Responsible for pulsatile right supra-clavicular mass
    78. 78. Schematic Doppler waveforms of VA
    79. 79. High-resistance flow in vertebral artery High-resistance flow No diastolic component Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131. Distal VA stenosis or occlusion Hypoplastic vertebral artery Differential diagnosis: Dizziness Unsteady walking Correlation with symptoms
    80. 80. Vertebral artery occlusion V2 Black & white US Color Doppler Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    81. 81. Route of flow in left vertebral steal Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    82. 82. 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
    83. 83. Vertebral-to-subclavian steal Presteal Incomplete steal Complete steal Compared to bunny in profile Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704.
    84. 84. 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 Kliewer MA et al. Am J Roentgenol 2000 ; 174 ; 815 – 9. Inflation of pressure cuff on arm for 3 min & rapid deflation* Pre-steal More pronounced steal
    85. 85. 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 Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575.
    86. 86. 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
    87. 87. Disadvantages of power mode Doppler • Does not provide direction of flow New machines provide direction of flow in power mode • Does not provide velocity flow information • Very motion sensitive (poor temporal resolution)
    88. 88. 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
    89. 89. Fibromuscular dysplasia Middle age women – Renal arteries – String of beads pattern Alternating zones of vasoconstriction & vasodilation for 3 – 5 cm ICA frequently – VA less frequently Usually bilateral Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. ICA
    90. 90. 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
    91. 91. Carotid & vertebral dissection • Spontaneous dissection Bleeding from vasa vasorum Most common ICA & VA (atlas loop) Intramural hematoma Pain – Stenosis – Horner • Vascular injury Iatrogenic: puncture – surgery CCA Intramural hematoma ± intimal tear • Stanford A dissection Intimal rupture in ascending aorta CCA Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
    92. 92. Dissection of aorta & cervical arteries Patho-anatomy Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Intimal rupture with false lumen Open or secondarily thrombosed Aorta External intramural hematoma Lumen constriction Rare intimal rupture Cervical
    93. 93. Spontaneous dissection of ICA Asymmetric wall hematoma – Lumen stenosis – Expansion to outside Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Diagnostic criteria (one sufficient) Intramural hematoma Intimal rupture/double lumen Distal stenosis or occlusion Symptoms: acute pain, Horner, Course: recanalization in few weeks
    94. 94. Spontaneous dissection of VA Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Wall hematoma in V1 Diagnostic criteria (one sufficient): Intramural hematoma (asymmetric, not concentric) Intimal rupture/double lumen (rare) Double lumen in V2
    95. 95. Thoracic aortic dissection Stanford classification Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Type B Dissection of descending aortaDissection of ascending aorta Possible continuation to supraaortic vessels Type A
    96. 96. Dissection of common carotid artery Stanford A Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Transverse view Longitudinal view Detection of two lumina & dissection membrane
    97. 97. Dissection of CCA / Stenosis Residuum after end of aortic dissection Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Doppler of true lumen Enlargement of false lumen before cranial end Doppler of false lumen Stenosis of true lumen
    98. 98. 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
    99. 99. Vasospasm • Causes Migraine, eclampsia, vasculitis, drug abuse, idiopat • Incidence Rarely identified (short duration) Occur frequently & remain undetected • Symptoms Cerebral or ocular ischemia • US Direct &/or indirect signs of severe stenosis Far above bifurcation – Sometimes bilateral Complete regression in hours to days – Relapse • Dd Dissection: wall hematoma – regression in weeks • Treatment Calcium antagonists Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
    100. 100. Vasospasm Janzarik WG et al. Stroke 2006 ; 37 : 2170 – 2173. Severe narrowing of ICA No stenosis detected 4 days later
    101. 101. 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
    102. 102. Extra-cranial ICA aneurysms Clevert DA et al. Clin Hemorheology Microcirculation 2008 ; 39 : 133 – 146. Color Doppler US Power Doppler US Uncomplete delineation of aneurysm – Thrombi could not be excluded Difficult definition for extracranial carotid artery aneurysms due to normal dilatation of bulb
    103. 103. ICA aneurysm / Parietal thrombosis Terborg C et al. Ultraschall Med 2007 ; 28 : 216 – 218. Aneurysm of proximal ICA Parietal thrombus & homogeneous thickening of vessel wall Longitudinal section Transversal section
    104. 104. CCA aneurysm / Rupture Clevert DA et al. Clin Hemorheology Microcirculation 2008 ; 39 : 133 – 146.
    105. 105. CCA pseudoaneurysm / Rare One month after bilateral neck dissection Flor N et al. J Laryngol Otol 2007 ; 121 : 497 – 500. CCA Pseudoaneurysm Large connecting neck Color Doppler US CE multidetector CT CCA Pseudoaneurysm Large connecting neck
    106. 106. 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
    107. 107. Arterio-venous fistula Attempt to perform US-guided jugular catheter insertion Clevert DA et al. Ultraschall Med 2010 ; 31 : 610 – 612. Turbulent flow in fistula track High-velocity turbulent flow in track Suspicion of communication between CCA & IJV CCA IJV
    108. 108. 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
    109. 109. Doppler ultrasound in arteritis “macaroni sign” & “halo sign” • 2 types Takayasu Young female – SCA & CCA Horton Old female – SCA, AA & Temporal A Cannot be differentiated using US • US signs Macaroni Concentric hypoechoic wall thickening Halo Dark halo around colorful lumen All grades of stenosis – Thrombotic vessel • Dd Dissection Eccentric hypoechoic wall thickening Pronounced outward expansion Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
    110. 110. Takayasu’s arteritis Young female – SCA [„pulseless‟ disease] – CCA CCA Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599. Long hypoechoic wall thickening Visualized in color Doppler as dark halo around vascular lumen
    111. 111. Horton's arteritis / Giant cell arteritis Concentric hypoechoic wall thickening Superficial temporal artery VA – Longitudinal view VA – Transverse view Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
    112. 112. 1 sAUROC: Summary Area Under Receiver Operating Characteristic 2 DOR: Diagnostic Odds Ratio Ball EL et al. Br J Surg 2010 ; 97 : 1765 – 1771. MA of US in diagnosis of temporal arteritis Halo sign versus temporal artery biopsy 9 studies – 357 patients Sensitivity 75% (67 – 82) Specificity 83% (78 – 88) sAUROC1 0.868 DOR2 17.96 (6.72 – 47.99) Heterogeneity I2 = 27%, P < 0.204 US relatively accurate for diagnosis of temporal arteritis US as first-line investigation, biopsy if negative scan
    113. 113. 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
    114. 114. Carotid body tumor / Rare Histology Paraganglioma of low malignant potential Presentation Palpable neck mass – Headache – Neck pain US Highly vascular mass in carotid bifurcation Arteriography Performed preoperatively – Embolization Treatment Resection to prevent local adverse events: Laryngeal nerve palsy – carcinoma invasion Result Local recurrence 6% – Distant metastasis 2%
    115. 115. Carotid body tumor Highly vascular mass in carotid bifurcation Zwiebel WL. Introduction to vascular ultrasonography. W.B. Saunders, Philadelphia, USA, 4th edition, 2000.
    116. 116. 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
    117. 117. Diagnosis of idiopathic carotidynia International Headache Society (IHS)1 • At least one of following over CA: Tenderness Swelling Increased pulsations • Pain over affected side of neck that may project to head • Appropriate investigations without structural abnormality Recent publications demonstrate radiological findings2 • Self-limiting syndrome of less than 2 weeks duration 1 International Headache Society. Cephalalgia 1988 ; 8 (Suppl 7) : 1 – 96. 2 Kosaka N et al. Eur Radiol 2007 ; 17 : 2430 – 2433.
    118. 118. Idiopathic carotidynia US findings comparable to dissection Kosaka N et al. Eur Radiol 2007 ; 17 : 2430 – 2433. Enhanced tissue around carotid artery CE T1-weighted MRIUS of distal CCA Hypo-echoic soft tissue around carotid artery Three months later Resolution of abnormal soft tissue
    119. 119. Spontaneous dissection & carotidynia Spontaneous dissection Carotidynia Location Beyoud bifurcation At or near bifurcation Thickening layers One wall layer 2 wall layers Stenosis May be detectable Not detectable Pain Head Neck MRI Native enhancement Enhancement after CAs In unclear cases, MRI enables differentiation Arning C et al. Ultraschall Med 2008 ; 29 : 576 – 599.
    120. 120. 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
    121. 121. Effect of extra-carotid diseases • Idiopathic dilated cardiomyopathy • Aortic regurgitation • Aortic stenosis • Stenosis of right innominate artery or origin of LCCA • High & low PSV in CCA • Stenosis of intra-cranial ICA
    122. 122. Idiopathic dilated cardiomyopathy Pulsus alternans Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704. PSV oscillating between two levels on sequential beats Cardiac rhythm remains regular throughout
    123. 123. Aortic regurgitation Bisferious waveform [“beat twice” in Latin] Kallman CE et al. Am J Roentgenol 1991 ; 157 : 403 – 407. Rohren EM et al. AJR 2003 ; 181 : 169 5– 1704. Two systolic peaks separated by midsystolic retraction Dicrotic notch Found also with hypertrophic obstructive cardiomyopathy
    124. 124. Severe aortic regurgitation Rohren EM et al. Am J Roentgenol 2003 ; 181 : 1695 – 1704. Normal or elevated PSV followed by precipitous decline Revered flow during diastole Water-hammer spectral appearance CCA
    125. 125. Aortic stenosis Scoutta LM et al. Ultrasound Clin 2006 ; 1 : 133 – 159. RCCA – Tardus-Parvus LCCA – Tardus-Parvus RVA – Tardus-Parvus
    126. 126. Right inominate artery stenosis RCCA – Tardus-Parvus LCCA – Normal waveform RVA – Reversed flow Scoutta LM et al. Ultrasound Clin 2006 ; 1 : 133 – 159.
    127. 127. Right inominate artery stenosis Zwiebel WJ, Pellerito JS. Introduction to Vascular Ultrasonography. 5th ed. Philadelphia: Elsevier Saunders; 2005. RICA : to-and-frow flow RCCA : to-and-frow flow RVA : reversed flow RSCA : damped flow Right carotid steal
    128. 128. High cardiac output: Hypertensive patients Young athletes High flow > 125 cm/sec in both CCAs Poor cardiac output: Cardiomyopathies Valvular heart disease Extensive myocardial infarction Low flow < 45 cm/sec in both CCAs Tahmasebpour HR et al. RadioGraphics 2005 ; 25 : 1561 – 1575. Arrhythmias can be real problem Normal PSV in CCA (45 – 125 cm/sec)
    129. 129. ICA High-grade stenosis distally (intracranial ICA) Major occlusive lesions of cerebral arteries (MCA, ACA) Massive spasm of cerebral arteries from intracranial hemorrhage Stenosis of intra-cranial ICA High resistance waveform Abropoulos NL et al. Vasc Endovascular Surg 2007 ; 41 : 417 – 427.
    130. 130. References Elsevier – 2005 Springer-Verlag – 2011 C. Arning et al. Ultraschall Med 2008 ; 31 : 576 – 599.
    131. 131. Thank You

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