Carotid artery stenosis: carotid duplex and carotid doppler ultrasonography help diagnose.

Clinical bottom line (level 1a)

  1. In patients with suspected carotid artery stenosis, carotid duplex ultrasonography, carotid doppler ultrasonography and magnetic resonance angiography are very helpful at ruling occlusion in and out.
  2. Carotid duplex ultrasonography and carotid doppler ultrasonography are very helpful at ruling 70% and 50% stenosis in and out.
Blakeley et al: Annals of Internal Medicine 1995; 122 (5): 360-367
Expires February 2003

The study

Systematic review of diagnostic testing of
  • Patients: extracranial carotid artery disease
  • Intervention: noninvasive tests compared with carotid angiography
  • Outcome: diagnosis


    • Articles found in English using MEDLINE, 1977 to 1993 (search terms: oculoplethysmography, ultrasonography, digital subtraction angiography, cerebral angiography and magnetic resonance imaging, and vertebral arteries, basilar arteries and carotid arteries ) and additional articles listed in the bibliographies of standard neurology texts and references cited in accepted articles were also included.

    Selection criteria: as above
    Appraisal criteria: detailed in text
    Articles excluded if: tests were not compared with carotid angiography, angiographic results were not separated to allow for specific identification of occluded arteries, reference standard results could not be classified into a contingency table according to degree of stenosis

    70 studies involving 6406 patients were included.

    The evidence


    diagnostic test number of patients sensitivity for
    carotid stenosis of 100%, 70% and 50%
    (95% CI)    		 specificity for
    carotid stenosis of 100%, 70% and 50%
    (95% CI)    		 LR+ LR-
    carotid duplex ultrasonography to diagnose occlusion 448 81.0%
    (77.0% to 84.0%)     		98.0%
    (98.0% to 98.0%)     		40.5 0.19
    carotid doppler ultrasonography to diagnose occlusion 393 85.0%
    (78.0% to 88.0%)     		98.0%
    (97.0% to 99.0%)     		42.5 0.15
    magnetic resonance angiography to diagnose occlusion 89 81.0%
    (75.0% to 85.0%)     		98.0%
    (97.0% to 99.0%)     		40.5 0.19
    carotid duplex ultrasonography to diagnose 70% stenosis 794 84.0%
    (80.0% to 86.0%)     		86.0%
    (84.0% to 88.0%)     		6.0 0.19
    carotid doppler ultrasonography to diagnose 70% stenosis 547 83.0%
    (80.0% to 85.0%)     		86.0%
    (84.0% to 88.0%)     		5.9 0.20
    carotid duplex ultrasonography to diagnose 50% stenosis 1755 85.0%
    (83.0% to 87.0%)     		85.0%
    (83.0% to 87.0%)     		5.7 0.18
    carotid doppler ultrasonography to diagnose 50% stenosis 1377 85.0%
    (83.0% to 87.0%)     		85.0%
    (83.0% to 87.0%)     		5.7 0.18
    total 6406

    Citation

    1. Blakeley DD, Oddone EZ, Hasselblad V, et al: Noninvasive carotid artery testing: A meta-analytic review. Annals of Internal Medicine 1995; 122 (5): 360-367
    Contributor: Clare Wotton and Musab Hayatli, February 2000
    Reviewer:

    Clinical Question.
    Patient carotid artery stenosis
    Intervention or Exposure noninvasive tests
    Comparison carotid angiography
    Outcome diagnosis