Learning objectives
To know the indications of carotid Doppler ultrasonography.
To review the technical parameters to have into account to perform a correct sonographic examination.
To recognize and illustrate the echographic findings in normal conditions and in most frequent carotid pathology.
Background
The carotid stenotic pathology is the cause of between 20-30% of stroke and transient ischemic attacks (TIA).
Most ischemic stroke episodes are due to embolisms as a result of thrombus formation due to hemodynamic alterations in carotid artery stenosis or migration of plaque fragments.
The major risk factors for carotid artery stenosis include older age,
male sex,
hypertension,
smoking,
hypercholesterolemia,
diabetes mellitus,
and heart disease.
Carotid Doppler ultrasonography is the preferred imaging modality for screening,
diagnosis and monitoring of arteriosclerosis of extracranial arteries.
Among all...
Findings and procedure details
ULTRASOUND MODALITIES(Fig. 1)
Gray scale or B-mode: it is use to evaluate the arteries anatomy and non vascular anormalities (plaques morphology,
intima-media thicknes…).
Color Doppler: assessment of vascular flow and direction.
It enables rapid identification of abnormal blood flow,
but has low sensitivity.
Spectral Doppler: graphic representation of the flow.
It allows to evaluate the speed and direction of the flow.
MAIN TECHNICAL PARAMETERS
Doppler angle: ideally it should be a 45o-60o angle,
in wich range a linear relation exists between velocity and the Doppler...
Conclusion
Carotid Doppler ultrasound allows to assess carotid pathology with great reliability,
but requires a systematic and careful study.
It is important to know and optimize the technical parameters that can affect the accuracy of the sonographic examination.
The sonographic features about the stenosis percentage and plaque morphology guide surgical decision.
References
Whal Lee.
General principles of carotid Doppler ultrasonography.
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2014 Jan; 33(1): 11–17.
Tahmasebpour HR,
Buckley AR,
Cooperberg PL,
Fix CH.
Sonographic examination of the carotid arteries.
Radiographics.
2005 Nov-Dec;25(6):1561-75.
Grant EG,
Benson CB,
Moneta GL et-al.
Carotid artery stenosis: gray-scale and Doppler US diagnosis-Society of Radiologists in Ultrasound Consensus Conference.
Radiology.
2003;229 (2): 340-6.
von Reutern GM,
Goertler MW,
Bornstein NM et-al.
Grading carotid stenosis using ultrasonic methods.
Stroke.
2012;43 (3): 916-21.
Hathout GM,
Fink JR,
El-saden SM et-al.
Sonographic NASCET index: a new...
