The question of how to classify carotid stenosis has been vexing us since
Unfortunately, Anatomy/Velocity Correlation is futile, in spite of our
confidence to the contrary.
Beach KW, Leotta DF, Zierler RE., Carotid Doppler velocity measurements
and anatomic stenosis: correlation is futile., Vasc Endovascular Surg.
from the Ultrasound Reading Center and the D.E. Strandness Jr. Vascular
Laboratory at University of Washington Medical Center, University of
Washington, Seattle, WA 98195, USA.
BACKGROUND: Duplex ultrasound with Doppler velocimetry is widely used to
evaluate the presence and severity of internal carotid artery stenosis;
however, a variety of velocity criteria are currently being applied to
classify stenosis severity. The purpose of this study is to compare
published Doppler velocity measurements to the severity of internal
carotid artery stenosis as assessed by x-ray angiography in order to
clarify the relationship between these 2 widely used approaches to assess
carotid artery disease.
METHODS: Scatter diagrams or "scattergrams" of correlations between
Doppler velocity measurements and stenosis severity as assessed by x-ray
contrast angiography were obtained from published articles for native and
stented internal carotid arteries. The scattergrams were graphically
digitized, combined, and segmented into categories bounded by 50% and 70%
diameter reduction. These data were combined and divided into 3 sets
representing different velocity parameters: (1) peak systolic velocity,
(2) end-diastolic velocity, and (3) the internal carotid artery to common
carotid artery peak systolic velocity ratio. The horizontal axis of each
scattergram was transformed to form a cumulative distribution function,
and thresholds were established for the stenosis categories to assess data
RESULTS: Nineteen publications with 22 data sets were identified and
included in this analysis. Wide variability was apparent between all 3
velocity parameters and angiographic percent stenosis. The optimal peak
systolic velocity thresholds for stenosis in stented carotid arteries were
higher than those for native carotid arteries. Within each category of
stenosis, the variability of all 3 velocity parameters was significantly
lower in stented arteries than in native arteries.
CONCLUSION: Although Doppler velocity criteria have been successfully used
to classify the severity of stenosis in both native and stented carotid
arteries, the relationship to angiographic stenosis contains significant
variability. This analysis of published studies suggests that further
refinements in Doppler velocity criteria will not lead to improved
correlation with carotid stenosis as demonstrated by angiography.
On Tue, 9 Oct 2012, Matthew Smith wrote:
> i've seen the diastolic velocities and ICA/CCA ratio disregarded by reading docs in cases of moderate stenosis, while being viewed as more
> important in determining cases of severe stenosis (surgery is the point at which they have a hard, well-defined line). Clinically it makes
> sense, if a patient has "mild to moderate" plaque and a 45% stenosis they should probably be followed up regularly, just as someone with
> "moderate plaque" and a 51% stenosis. They both have about a 50% stenosis. Someone at the upper end of the 50-69% category would likely
> have no problem meeting the end diastolic criteria, you're talking about patients at the upper limit of mild stenosis being placed in the
> lower limits of the moderate category. I doubt any imaging modality, in reality, is sensitive to a 6% difference in stenosis, it's all
> subject to measurement error, and ultimately someone's judgment call. It may sometimes skew your QA correlations, but most of these
> patients wouldn't probably have additional imaging studies anyway, unless symptomatic or your study is suboptimal or its accuracy
> questioned. if this is truly throwing off your accreditation/QA stats you should probably just ask the reading doc about their line of
> thinking (nicely of course).
> On Tue, Oct 9, 2012 at 10:20 AM, Kimberly Higgins <[log in to unmask]> wrote:
> We have to meet BOTH peak systolic and end diastolic. Otherwise, why do you have the criteria written that way if you dont use
> it?? ICAVL would probably question it. I have also discovered that your QA probably will not correlate.
> From: UVM Flownet [[log in to unmask]] On Behalf Of Deidre [[log in to unmask]]
> Sent: Tuesday, October 09, 2012 11:39 AM
> To: [log in to unmask]
> Subject: Re: carotid correlations
> At our lab we use 3 criterion and to put it in any category it must meet 2out of 3 of the criterion we established. PSV EDV
> AND RATIO
> Sent from my LG phone
> "Myers, Ruth" <[log in to unmask]> wrote:
> >Hello flownetters- I have a question about carotid correlations. (Actually probably more about interpretation, but here
> goes....) If the systolic velocity meets the set criteria for a 50-69% stenosis, but the diastolic does not, should it be
> read based upon the systolic velocity alone?
> >For example our criteria is 140 cm/sec systolic with 40 cm/sec diastolic = 50-69% stenosis. However, my doc often reads
> something that might be 142 cm/sec systolic but 25 cm/sec diastolic. Am I okay to say that he has read correctly using the
> diagnostic criteria when I am doing my correlations?
> >Ruth Myers, BS, CNMT, RDMS, RVT
> >Lead Technologist
> >Vascular Laboratory
> >Beebe Medical Center
> >Lewes, Delaware
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