Abstract
Duplex sonography combines the ability to real time image the carotid artery and accurately sample the vessel using pulsed Doppler. The flow information is presented graphically as velocity vs. time (Figure 8.1). It has become possible to color encode the velocity information and superimpose this upon the 2D gray-scale image — color flow Doppler. The color of each pixel displayed is the mean velocity and not peak velocity. It is standard practice that color flow Doppler is used quickly to locate and identify vessels and areas of turbulence; pulsed Doppler is then used to quantify flow accurately (Figure 8.2). ‘Power flow’ Doppler is a more recent development that analyzes the amplitude of the returning signal rather than frequency and direction. The signal is sensitive to flow, has a high signal to noise ratio and is less dependent upon the angle of insonation than pulsed or color flow Doppler. However, the image does not produce information on either peak velocity or direction of flow and is one of anatomy rather than function.
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References
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991; 325:445–453.
European Carotid Surgery Trialists Collaborative Group. MRC European Carotid Surgery Trial: Interim results for symptomatic patients with severe (70–99%) or with mild (1–29%) carotid stenosis. Lancet 1991; 337:1235–1242.
Alexandrov AV, Bladin CF, Maggisano R, Norris JW. Measuring carotid stenosis: Time for a reappraisal. Stroke 1993; 24:1292–1296.
Thiele BL, Jones AM, Hobson RW et al. Standards in the noninvasive cerebrovascular testing: Report from the Committee on Standards for Noninvasive Vascular Testing of the Society of Vascular Surgery and the North American Chapter of the International Society of Cardiovascular Surgery. J Vasc Surg 1992; 15:495–503.
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 Vasc Surg 1994; 19:818–828.
Moneta GL, Edwards M, 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 Vasc Surg 1993; 17:152–159.
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 Vasc Surg 1994; 20:642–649.
Kirsch JD, Wagner LR, James WE et al. Carotid artery occlusion: Positive predictive value of duplex sonography compared with arteriography. J Vasc Surg 1994; 19:642–649.
Hayward JK, Davies AH, Lamont PM. Carotid plaque morphology: A review. Eur J Vasc Endovasc Surg 1995; 9:368–374.
Hankey JG, Warlow CP, Molyneux AJ. Complications of cerebral angiography for patients with mild carotid territory ischaemia being considered for carotid endarterectomy. J Neurol Neurosurg Psychiat 1990; 53:542–548.
Heiserman JE, Dean BL, Hodak JA et al. Neurological complications of cerebral angiography. Am J Neuroradiol 1994; 15:1401–1407.
Warnock NG, Bergvall U, Powell T. Complications of intra-arterial digital subtraction angiography in patients investigated for cerebral vascular disease. Br J Radiol 1993; 66:855–858.
Grzyska U, Freitag J, Zeumer H. Selective cerebral intra-arterial DSA: complication rate and control of risk factors. Neuroradiology 1990; 32:296–299.
Chikos PM, Fisher LD, Hirsch JH et al. Observer variability in evaluating carotid artery stenosis. Stroke 1983; 14:885–892.
Polak JF, Dobkin GR, O’Leary DH, Wang A-M, Cutler SS. Internal carotid artery stenosis: Accuracy and reproducibility of color-Doppler-assisted duplex imaging. Radiology 1989; 173:793–798.
Schuler JJ, Flanigan DP, Tim LT et al. The effect of carotid syphon stenosis on stroke rate, death, and relief of symptoms following elective carotid endarterectomy. Surgery 1983; 92:1058–1065.
Edelman RR, Hesselink JR. Clinical management resonance imaging. WB Saunders, 1990:147–179.
Turnipseed WD, Kenneil TW, Turski PA et al. Magnetic resonance angiography and duplex imaging: noninvasive tests for selecting symptomatic carotid endarterectomy candidates. Surgery 1993; 114:643–649.
Anderson CM, Saloner D, Lee RE et al. Assessment of carotid artery stenosis by MR angiography: Comparison with X-ray angiography and color-coded Doppler ultrasound. Am J Neuroradiol 1992; 13:989–1003.
Patel MR, Klufas RA, Kim D et al. MR angiography of the carotid bifurcation: artifacts and limitations. Am J Roentgenol 1994; 162:1431–1437.
Cumming JM, Morrow IM. Carotid artery stenoses: A prospective comparison of CT angiography and conventional angiography. Am J Radiol 1994; 163:517–523.
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Gaines, P.A., Hodgson, T.J., Aldoori, M.I., Beard, J.D. (1996). The investigation of extracranial carotid disease. In: Salmasi, AM., Strano, A. (eds) Angiology in Practice. Developments in Cardiovascular Medicine, vol 187. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-5406-2_8
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DOI: https://doi.org/10.1007/978-94-011-5406-2_8
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