9/17/2023 0 Comments Carotid doppler results explained![]() 24 ⇓- 26īecause of these recent gains in understanding, our attention is being turned to the carotid plaque itself rather than the lumen alone. 20, -, 23 The disconnect between stenosis severity and stroke risk is an area of active investigation, especially in plaques causing <50% stenosis, which are increasingly being considered as a potential cause of embolic strokes that are otherwise of uncertain etiology. 16 We have learned that the degree of luminal stenosis does not necessarily correlate with the volume of plaque, 17, -, 19 that many plaque features besides luminal stenosis can directly contribute to ischemia, and that these high-risk features can lead to ischemic symptoms regardless of the degree of stenosis. Infarctions secondary to carotid disease are thought to be caused by not only the flow-reduction from stenotic plaque but also artery-to-artery emboli occurring after fibrous cap rupture. 9 ⇓ ⇓ ⇓ ⇓ ⇓- 15 Recently, our understanding of the contributions of plaque features to cerebrovascular ischemia has altered how we evaluate carotid plaque. Traditionally, imaging risk assessment has been based on the degree of arterial narrowing as measured by the NASCET criteria, which have been used as the basis for randomized clinical trials and for many stroke classification schemes. ![]() ![]() 6, 7 With improvement in medical management for treating patients with carotid artery stenosis, the annual risk of stroke has decreased in asymptomatic patients to ∼1%, 8 which has made the need to appropriately risk-stratify patients even more critical. We will also include practical considerations and comparisons with other imaging modalities.Įxtracranial atherosclerosis is an important contributor to stroke, accounting for 15%–20% of all ischemic strokes. For each plaque feature, we will summarize the existing literature, associating each feature with stroke risk. In this review, we will describe technical considerations when performing CTA and then provide detailed descriptions of individual plaque characteristics that can be evaluated on CTA. While identifying thrombosis and the degree of stenosis on CTA is necessary in selecting patients for intervention, other plaque features evident on CTA are also valuable in determining the risk of stroke or TIA and in aiding management decisions. In addition to providing accurate information regarding the degree of luminal stenosis, CTA examinations can also provide rich detail regarding plaque morphology and features, given their superb spatial resolution. Although CTA does not have the same prospective evidence as MR imaging and ultrasound for predicting future cerebrovascular disease, CTA does provide valuable information regarding plaque characteristics that should not be ignored.ĬTA of the head and neck is a commonly acquired examination to evaluate vessel patency in the setting of cerebrovascular ischemia, especially in the work-up of acute ischemic infarction. 3 ⇓- 5 CTA is often overlooked as a method for providing detailed evaluation of plaque characteristics, and it has certain benefits in terms of accessibility and ease of use in clinical workflow not present with multisequence MR imaging characterization of carotid plaque. 1, 2 In addition to MR imaging, contrast-enhanced sonography is also a powerful tool for evaluating carotid plaque vulnerability. Much of the literature of vessel wall imaging has centered on MR imaging because of its impressive contrast resolution and high sensitivity for identifying high-risk plaque features. Despite decades of using a degree of luminal stenosis as the primary determinant of treatment for patients with carotid artery stenosis, there has been a recent trend toward adopting advanced imaging techniques to provide a more complete plaque evaluation for more accurate risk assessment. Recent advances in vessel wall imaging have spurred a paradigm shift in the evaluation of carotid plaque. ABBREVIATIONS: IPH intraplaque hemorrhage LRNC lipid-rich necrotic core ![]()
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