Ultrasound assessment of carotid arterial atherosclerotic disease

Ultrasound assessment of carotid arterial atherosclerotic disease has become the first choice for carotid artery stenosis screening, permitting the evaluation of both the macroscopic appearance of plaques as well as flow characteristics in the carotid artery.

This article focus on internal carotid artery (ICA) stenosis, reporting both criteria: the one published by Society of Radiologists in Ultrasound 2 and the Sonographic NASCET Index 1.

Please refer to the article on extracranial carotid artery stenosis for a general discussion involving carotid stenosis and other image modalities involved on it.

Society of Radiologists in Ultrasound (SRU) consensus

This consensus developed recommendations for the diagnosis and stratification of ICA stenosis 2.

[PSV = peak systolic velocity; EDV = end diastolic velocity; ICA = internal carotid artery; CCA = common carotid artery]

  • normal:
    • ICA PSV is <125 cm/sec and no plaque or intimal thickening is visible sonographically
    • additional criteria include ICA/CCA PSV ratio <2.0 and ICA EDV <40 cm/sec
  • <50% ICA stenosis:
    • ICA PSV is <125 cm/sec and plaque or intimal thickening is visible sonographically
    • additional criteria include ICA/CCA PSV ratio <2.0 and ICA EDV <40 cm/sec
  • 50-69% ICA stenosis:
    • ICA PSV is 125-230 cm/sec and plaque is visible sonographically
    • additional criteria include ICA/CCA PSV ratio of 2.0-4.0 and ICA EDV of 40-100 cm/sec
  • ≥70% ICA stenosis but less than near occlusion:
    • ICA PSV is >230 cm/sec and visible plaque and luminal narrowing are seen at gray-scale and colour Doppler ultrasound (the higher the Doppler parameters lie above the threshold of 230 cm/sec, the greater the likelihood of severe disease)
    • additional criteria include ICA/CCA PSV ratio >4 and ICA EDV >100 cm/sec
  • near occlusion of the ICA:
    • velocity parameters may not apply, since velocities may be high, low, or undetectable
    • diagnosis is established primarily by demonstrating a markedly narrowed lumen at colour or power Doppler ultrasound
  • total occlusion of the ICA:
    • no detectable patent lumen at gray-scale US and no flow with spectral, power, and colour Doppler ultrasound
    • there may be compensatory increased velocity in the contralateral carotid
Sonographic NASCET Index

This study proposed the incorporation of distal ICA flow velocity information on the conventional carotid Doppler study improving the diagnostic accuracy of PSV 1.

  • <15% stenosis:
    • deceleration spectral broadening with a peak systolic velocity (PSV) <125 cm/s
  • 16-49% stenosis:
    • pansystolic spectral broadening with a PSV <125 cm/s

  • 50-69% stenosis:
    • pansystolic spectral broadening with a PSV of >125 cm/s
      and
    • end diastolic velocity (EDV) <110 cm/s or ICA/CCA PSV ratio >2 but <4
  • 70-79% stenosis:
    • pansystolic spectral broadening with PSV >270 cm/s
      • or
      • EDV >110 cm/s
        or
      • ICA/CCA PSV ratio >4
  • 80-99% stenosis: EDV >140 cm/s
  • complete occlusion: no flow; terminal thump
Ultrasound - general index
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Article information

rID: 9404
System: Vascular
Synonyms or Alternate Spellings:
  • Ultrasound for internal carotid artery stenosis
  • Carotid artery stenosis - ultrasound criteria
  • Carotid doppler stenosis

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Cases and figures

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    Case 1: 50-69 % R-ICA stenosis
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    Color Doppler ima...
    Case 2: CCA occlusion and reversed flow in ECA
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    Internal carotid ...
    Case 3
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    Extreme increases...
    Case 4
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    In view of the no...
    Case 5
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    Left bulb.
    Case 6: markedly narrowed lumen
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    Right common caro...
    Case 7: ICA PSV 367 cm/s
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    Left ICA.
    Case 8: ICA PSV 631 cm/s
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    Case 9
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