Carotid doppler results explained8/26/2023 The worksheet is submitted with paper, film, photocopied or electronic versions of the images to the UWURC. įor each of the 16 or more spectral waveforms, systolic and diastolic velocities are measured and transcribed along with the Doppler angles (from the associated B-mode images) to a standard worksheet. ![]() The additional variables include: the presence of a moderate or severe contralateral stenosis, cerebral territory perfused, completeness of the circle of Willis, ipsilateral collateral flow, vertebral flow and method of revascularization. However, detailed publications demonstrate that although satisfactory sensitivities and specificities can be obtained by associating selected angiographic classifications with particular Doppler measurements, the relationship between Doppler measurements and angiography is not a narrow monotonic line, but a multivariate relationship. Some publications use other angiographic categories with divisions at 60%, 70% or other values.Ī variety of Doppler velocity measurement methods are used to classify arteries into the proper angiographic categories. The reference standard for the classification method is X-ray contrast angiography. The method and associated criteria for stenosis classification were developed in the decade prior to 1990. One often used classification scheme is: 1) no significant stenosis (< 50%DR), 2) moderate stenosis (50%-79%DR), 3) severe stenosis (80%-99%DR), and 4) occluded. Doppler velocity waveforms are gathered from the common and internal carotid arteries to detect local elevated blood velocity as a marker of arterial stenosis allowing categorical classification of the right and left common and internal carotid arteries into clinically useful categories. Noninvasive ultrasonic duplex Doppler examination has been a standard method for the clinical evaluation of the carotid arteries for a third of a century. Clinical trials of carotid artery revascularization methods such as carotid endarterectomy and carotid artery stenting are in progress to provide guidance to clinicians about the choice of therapy. Repair of carotid artery stenoses (carotid revascularization) has been shown to be effective in reducing the chance of embolic stroke from carotid plaque rupture and embolization to the brain. Because the goals of research examinations are different from those of clinical examinations, screening and diagnostic clinical examinations may require fewer velocity measurements. In clinical trails, a centralized reading center can unify the methods. DiscussionĪlthough ultrasonic duplex Doppler methods are widely used in carotid artery diagnosis, there is disagreement about how the examinations should be performed and how the results should be validated. The definition of peak systolic velocity varies between examiners when spectral broadening due to turbulence is present. ResultsĪngle adjusted Doppler velocity measurements produce higher values when higher Doppler examination angles are used. Doppler angle alignment errors greater than 3 degrees and Doppler velocity measurement errors greater than 0.05 m/s are corrected. ![]() The UWURC verifies all measurements against the images and waveforms for the database, which includes pre-procedure, post-procedure and annual follow-up examinations. ![]() Methodsĭoppler waveforms from 6 locations along the common carotid and internal carotid artery path to the brain plus the external carotid and vertebral arteries on each side using a Doppler examination angle of 60 degrees are evaluated. The University of Washington Ultrasound Reading Center (UWURC) provides a uniform examination protocol and interpretation of duplex Doppler velocity measurements. Noninvasive ultrasonic duplex Doppler velocimetry provides a precision method that can be used for recruitment qualification, pre-treatment classification and post treatment surveillance for remodeling and restenosis. Serial monitoring of patients participating in clinical trials of carotid artery therapy requires noninvasive precision methods that are inexpensive, safe and widely available.
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