Mayo Clinic Proceedings Home

Redefined Duplex Ultrasonographic Criteria for Diagnosis of Carotid Artery Stenosis


      To evaluate duplex ultrasongraphic criteria for the determination of 50 % or more and 70% or more stenosis of the diameter of the internal carotid artery based on conventional angiography in order to align ultrasongraphic diagnostic categories with current clinical management schemes.


      Between January 1, 1995, and June 30,1999, 915 patients underwent both carotid duplex ultrasonography and cerebral angiography within 30 days at Mayo Clinic, Rochester, Minn. Of these patients, 294 were excluded from this study because of occlusion of one or both of the internal carotid arteries or atypical Dow characteristics. In the remaining 621 patients (61 % male, 39% female; mean age, 67.7 years [range, 14-88 years]), 1218 vessels were available for correlation. Several Doppler ultrasongraphic velocity variables were compared with the angiographic findings by use of receiver operating characteristic curve analysis. The primary end point was verification of optimal ultrasongraphic criteria to diagnose 70% or more internal carotid artery stenosis. The secondary end point was establishment of threshold values to detect stenosis of 500/0 or more.


      At angiography, 382 patients had internal carotid arteries with 70% or more stenosis. Peak systolic and end diastolic velocities of the internal carotid artery and internal carotid artery:common carotid artery peak systolic velocity ratios were measured. For an internal carotid artery stenosis of 70% or more, a peak systolic velocity of 230 cm/s or more resulted in a sensitivity of 86.4%, a specificity of 90.1%, a positive predictive value of 82.7%, a negative predictive value of 92.3%, and an accuracy of 88.8% An end diastolic velocity of 70 cm/s or more and an internal carotid artery:common carotid artery ratio of 3.2 or more yielded similar values. For an internal carotid artery stenosis of 50% or more, a peak systolic velocity of 130 cm/s or more resulted in a sensitivity of 92.1%, a specificity of 89.50/0, a positive predictive value of 90.3%, a negative predictive value of 91.3%, and an overall accuracy of 90.8%. An internal carotid artery:common carotid artery ratio of 1.6 or more yielded similar values.


      In our ultrasonography laboratory, a carotid artery stenosis of 70% or more (for which carotid endarterectomy is typically recommended in symptomatic patients) is diagnosed reliably with the following duplex ultrasongraphic criteria: a peak systolic velocity of 230 cms or more, an end diastolic velocity of 70 cm/s or more, or an internal carotid artery:common carotid artery ratio of 3.2 or more.
      CCA (common carotid artery), CT (computed tomographic), ECST (European Carotid Surgery Trial), EDV (end diastolic velocity), ICA (internal carotid artery), NASCET (North American Symptomatic Carotid Endarterectomy Trial), PSV (peak systolic velocity), VA (Veterans Affairs)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Mayo Clinic Proceedings
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • North American Symptomatic Carotid Endartereclomy Trial Collaborators
        Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis.
        N Engl J Med. 1991; 325: 445-453
        • Mayberg MR
        • Wilson SE
        • Yatsu F
        • et al.
        Veterans Affairs Cooperative Studies Program 309 Trialist Group. Carotid endarterectomy and prevention of cerebral ischemia in symptomatic carotid stenosis.
        JMAM. 1991; 266: 3289-3294
        • Barnett HJM
        • Taylor DW
        • Eliasli M
        • et al.
        North American Symptomatic Carotid Endarterectomy Trial Collaborators. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis.
        N Engl J Med. 1998; 339: 1415-1425
        • Zwiebel WJ
        Doppler evaluation of carotid stenosis.
        in: Zwiebel WJ Introduction to Vascular Ultrasonography. 3rd ed. WB SaundersCo, Philadelphia, Pa1992: 123-132
        • Strandness Jr, DE
        Duplex Scanning in Vascular Disorders. Raven Press, New York, NY1990: 92-120
        • Huston III, J
        • Lewis BD
        • Wiebers DO
        • Meyer FB
        • Riederer SJ
        • Weaver AL
        Carotid artery: prospective blinded comparison of two-dimensional lime-of-flight MR angiography with conventional angiography and duplex US.
        Radiology. 1993; 186: 339-344
        • Cartier R
        • Cartier P
        • Fontaine A
        Carotid endarterectomy without angiography: the reliability of Doppler ultrasonography and duplex scanning in preoperative assessment.
        Can J Surg. 1993; 36: 41l-416
        • Dawson DL
        • Zierler RE
        • Strandness Jr, DE
        • Clowes AW
        • Kohler TR
        The role of duplex scanning and arteriography before carotid endarterectomy; a prospective study.
        J Vase Surg. 1993; 18: 673-680
        • Golledge J
        • Wright R
        • Pugh N
        • Lane IF
        Colour-coded duplex assessment alone before carotid endartereclomy.
        Br J Surg. 1996; 83: 1234-1237
        • Gortler M
        • Niethammer R
        • Widder B
        Differentiating subtotal carotid artery stenoses from occlusions by colour-coded duplex sonography.
        J Neurol. 1994; 241: 301-305
        • Horn M
        • Michelini M
        • Grcisler HP
        • Littooy FN
        • Baker WH
        Carotid endarterectomy without arteriography: the preeminent role of the vascular laboratory.
        Ann Vasc Surg. 1994; 8: 221-224
        • Karacagil S
        • Bergqvist D
        Reevaluation of duplex criteria for diagnosis of high-grade carotid artery stenosis: when do we need angiography and when can we operate without angiography?.
        Int Angiol. 1995; 14: 410-414
        • Muto PM
        • Welch HJ
        • Mackcey WC
        • O'Donnell TF
        Evaluation of carotid artery stenosis: is duplex ultrasonography sufficient?.
        Vase Surg. 1996; 24: 17-22
        • Nicolaides AN
        • Shifrin EG
        • Bradbury A
        • et al.
        Angiographic and duplex grading of internal carotid stenosis: can we overcome the confusion?.
        J Endovasc Surg. 1996; 3: 158-165
        • Padayachee TS
        • Cox TC
        • Modaresi KB
        • Colchester AC
        • Taylor PR
        The measurement of internal carotid artery stenosis: comparison of duplex with digital subtraction angiography.
        Eur J Vase Endovasc Surg. 1997; 13: 180-185
        • Turnipseed WD
        • Kennell TW
        • Turski PA
        • Acher CW
        • Hoch JR
        Combined use of duplex imaging and magnetic resonance angiography for evaluation of patients with symptomatic ipsilateral high-grade carotid stenosis.
        J Vase Surg. 1993; 17: 832-839
        • Young GR
        • Humphrey PR
        • Shaw MD
        • Nixon TE
        • Smith ET
        Comparison of magnetic resonance angiography, duplex ultrasound, and digital subtraction angiography in assessment of extracranial internal carotid artery stenosis.
        J Neurol Neurosurg Psychiatry. 1994; 57: 1466-1478
        • Moneta GL
        • Edwards JM
        • Chitwood RW
        • et al.
        Correlation of North American Symptomatic Carotid Endarterectomy Trial (NASCET) angiographic definition of 70% to 99% internal carotid artery stenosis with duplex scanning.
        J Vase Surg. 1993; 17: 152-157
        • Browman MW
        • Cooperberg PL
        • Harrison PB
        • Marsh Jl
        • Mallek N
        Duplex ultrasonography criteria for internal carotid stenosis of more than 70% diameter: angiographie correlation and receiver operating characteristic curve analysis.
        Can Assoc Radiol J. 1995; 46: 291-295
        • Faught WE
        • Mattos MA
        • van Bemmelen PS
        • et al.
        Color-flow duplex scanning of carotid arteries: new velocity criteria based on receiver operator characteristic analysis for threshold stenoses used in the symptomatic and asymptomatic carotid trials.
        J Vase Surg. 1994; 19: 818-827
        • Neale ML
        • Chambers JL
        • Kelly AT
        • et al.
        Reappraisal of duplex criteria to assess significant carotid stenosis with special reference to reports from the North American Symptomatic Carotid Endarterectomy Trial and the European Carotid Surgery Trial.
        J Vase Surg. 1994; 20: 642-649
        • Robinson ML
        • Sacks D
        • Perlmutter GS
        • Marinelli DL
        Diagnostic criteria for carotid duplex sonography.
        AJR Am J Roentgenol. 1988; 151: 1045-1049
        • Polak JF
        • Hunink MG
        • O'Leary DH
        Doppler US for internal carotid stenosis of 70% or more: ROC analysis [abstract].
        Radiology. 1991; 181: 133
        • Hunink MG
        • Polak JF
        • Barlan MM
        • O'Leary DH
        Detection and quantification of carotid artery stenosis: efficacy of various Doppler velocity parameters.
        AJR Am J Roentgenot. 1993; 160: 619-625
        • Van Leersum M
        • Van Leeuwen MS
        • Van der Schouw Y
        • Mali WPTM
        • Eikelboom BC
        New duplex threshold values for angiographically determined stenosis in the internal carotid artery in the light of the NASCET and ECST [abstract].
        Cardiovase Intervent Radial. 1995; 18: S62
        • Carpenter JP
        • Lexa FJ
        • Davis JT
        Determination of duplex Doppler ultrasound criteria appropriate to the North American Symptomatic Carotid Endarterectomy Trial.
        Stroke. 1996; 27: 695-699
        • Hood DB
        • Mattos MA
        • Mansour A
        • et al.
        Prospective evaluation of new duplex criteria to identify 70% internal carotid artery stenosis.
        J Vase Surg. 1996; 23: 254-262
        • AbuRahma AF
        • Robinson PA
        • Strickler DL
        • Alberts S
        • Young L
        Proposed new duplex classification for threshold stenoses used in various symptomatic and asymptomatic carotid endarterectomy trials.
        Ann Vase Surg. 1998; 12: 349-358
        • Grant EG
        • Duerinckx AJ
        • El Saden SM
        • et al.
        Ability to use duplex US to quantify internal carotid arterial stenoses: fact or fiction?.
        Radiology. 2000; 214: 247-252
        • Fillinger MF
        • Baker Jr, RJ
        • Zwolak RM
        • et al.
        Carotid duplex criteria for a 60% or greater angiographic stenosis: variation according to equipment.
        J Vasc Surg. 1996; 24: 856-864
        • Kuntz KM
        • Polak JF
        • Whittemore AD
        • Skillman JJ
        • Kent KC
        Duplex ultrasound criteria for the identification of carotid stenosis should be laboratory specific.
        Stroke. 1997; 28: 597-602
        • van Everdingen KJ
        • van der Grond J
        • Kappelle LJ
        Overestimation of a stenosis in the internal carotid artery by duplex sonography caused by an increase in volume flow.
        J Vase Surg. 1998; 27: 479-485
        • O'Leary DH
        • Clouse ME
        • Potter JE
        • Wheeler HG
        The influence of noninvasive tests on the selection of patients for carotid angiography.
        Stroke. 1985; 16: 264-267
        • Fox AJ
        How to measure carotid stenosis [editorial].
        Radiology. 1993; 186: 316-318
        • Earnest IV, F
        • Forbes G
        • Sandok BA
        • et al.
        Complications of cerebral angiography: prospective assessment of risk.
        AJR Am J Roentgenol. 1984; 142: 247-253
        • Busuttil SJ
        • Franklin DP
        • Youkey JR
        • Elmore JR
        Carotid duplex overestimation of stenosis due to severe contralateral disease.
        Am J Surg. 1996; 172: 144-147
        • Mansour MA
        • Mattos MA
        • Hood DB
        • et al.
        Detection of total occlusion, string sign, and preocclusive stenosis of the internal carotid artery by color-flow duplex scanning.
        Am J Surg. 1995; 170: 154-158
        • Hanley JA
        • McNeil BJ
        The meaning and use of the area under a receiver operating characteristic (ROC) curve.
        Radiology. 1982; 143: 29-36
        • European Carotid Surgery Trialists' Collaborative Group
        MRC European Carotid Surgery Trial: interim results for symptomatic patients with severe (70-99%) or with mild (0-29%) carotid stenosis.
        Lancet. 1991; 337: 1235-1243