OBJECTIVE
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.
PATIENTS AND METHODS
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.
RESULTS
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.
CONCLUSION
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.
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 accessOne-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:
Subscribe to Mayo Clinic ProceedingsAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
REFERENCES
- Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis.N Engl J Med. 1991; 325: 445-453
- Veterans Affairs Cooperative Studies Program 309 Trialist Group. Carotid endarterectomy and prevention of cerebral ischemia in symptomatic carotid stenosis.JMAM. 1991; 266: 3289-3294
- 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
- Doppler evaluation of carotid stenosis.in: Zwiebel WJ Introduction to Vascular Ultrasonography. 3rd ed. WB SaundersCo, Philadelphia, Pa1992: 123-132
- Duplex Scanning in Vascular Disorders. Raven Press, New York, NY1990: 92-120
- Carotid artery: prospective blinded comparison of two-dimensional lime-of-flight MR angiography with conventional angiography and duplex US.Radiology. 1993; 186: 339-344
- Carotid endarterectomy without angiography: the reliability of Doppler ultrasonography and duplex scanning in preoperative assessment.Can J Surg. 1993; 36: 41l-416
- The role of duplex scanning and arteriography before carotid endarterectomy; a prospective study.J Vase Surg. 1993; 18: 673-680
- Colour-coded duplex assessment alone before carotid endartereclomy.Br J Surg. 1996; 83: 1234-1237
- Differentiating subtotal carotid artery stenoses from occlusions by colour-coded duplex sonography.J Neurol. 1994; 241: 301-305
- Carotid endarterectomy without arteriography: the preeminent role of the vascular laboratory.Ann Vasc Surg. 1994; 8: 221-224
- 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
- Evaluation of carotid artery stenosis: is duplex ultrasonography sufficient?.Vase Surg. 1996; 24: 17-22
- Angiographic and duplex grading of internal carotid stenosis: can we overcome the confusion?.J Endovasc Surg. 1996; 3: 158-165
- The measurement of internal carotid artery stenosis: comparison of duplex with digital subtraction angiography.Eur J Vase Endovasc Surg. 1997; 13: 180-185
- 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
- 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
- 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
- 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
- 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
- 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
- Diagnostic criteria for carotid duplex sonography.AJR Am J Roentgenol. 1988; 151: 1045-1049
- Doppler US for internal carotid stenosis of 70% or more: ROC analysis [abstract].Radiology. 1991; 181: 133
- Detection and quantification of carotid artery stenosis: efficacy of various Doppler velocity parameters.AJR Am J Roentgenot. 1993; 160: 619-625
- 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
- Determination of duplex Doppler ultrasound criteria appropriate to the North American Symptomatic Carotid Endarterectomy Trial.Stroke. 1996; 27: 695-699
- Prospective evaluation of new duplex criteria to identify 70% internal carotid artery stenosis.J Vase Surg. 1996; 23: 254-262
- Proposed new duplex classification for threshold stenoses used in various symptomatic and asymptomatic carotid endarterectomy trials.Ann Vase Surg. 1998; 12: 349-358
- Ability to use duplex US to quantify internal carotid arterial stenoses: fact or fiction?.Radiology. 2000; 214: 247-252
- Carotid duplex criteria for a 60% or greater angiographic stenosis: variation according to equipment.J Vasc Surg. 1996; 24: 856-864
- Duplex ultrasound criteria for the identification of carotid stenosis should be laboratory specific.Stroke. 1997; 28: 597-602
- 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
- The influence of noninvasive tests on the selection of patients for carotid angiography.Stroke. 1985; 16: 264-267
- How to measure carotid stenosis [editorial].Radiology. 1993; 186: 316-318
- Complications of cerebral angiography: prospective assessment of risk.AJR Am J Roentgenol. 1984; 142: 247-253
- Carotid duplex overestimation of stenosis due to severe contralateral disease.Am J Surg. 1996; 172: 144-147
- 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
- The meaning and use of the area under a receiver operating characteristic (ROC) curve.Radiology. 1982; 143: 29-36
- 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
Article Info
Footnotes
Dr Lefsrud is now with St Paul Radiology, St Paul, Minn. Dr Robertson is now in Dallas, Tex.
Identification
Copyright
© 2000 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
