Contemporary carotid imaging: from degree of stenosis to plaque vulnerability
- PMID: 26230478
- DOI: 10.3171/2015.1.JNS142452
Contemporary carotid imaging: from degree of stenosis to plaque vulnerability
Abstract
Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is limited in sensitivity and specificity for detecting LRNC, plaque hemorrhage, and ulceration compared with MRI. Also summarized is how these advanced imaging techniques are being used in clinical practice to risk stratify patients with low- and high-grade carotid artery stenosis. For example, identification of IPH on MRI in patients with low-grade carotid artery stenosis is a risk factor for failure of medical therapy, and studies have shown that such patients may fair better with carotid endarterectomy (CEA). MR plaque imaging has also been found to be useful in identifying revascularization candidates who would be better candidates for CEA than carotid artery stenting (CAS), as high intraplaque signal on time of flight imaging is associated with vulnerable plaque and increased rates of adverse events in patients undergoing CAS but not CEA.
Keywords: AHA = American Heart Association; CAS = carotid artery stenting; CEA = carotid endarterectomy; CEUS = contrast-enhanced ultrasonography; CTA = CT angiography; DCE = dynamic contrast-enhanced; DSCT = dual-source CT; FDG = fluorodeoxyglucose; FSE = fast spin echo; Gd = gadolinium; HU = Hounsfield units; IPH = intraplaque hemorrhage; LRNC = lipid-rich necrotic core; MDCT = multidetector-row CT; MDCTA = MDCT angiography; MES = microembolic signal; MMP-9 = matrix metalloproteinase-9; MRA = MR angiography; MRI; PDW = proton density-weighted; SUV = standardized uptake value; SUVmax = maximal SUV; TBR = target-to-background ratio; TCD = transcranial Doppler ultrasonography; TIA = transient ischemic attack; TOF = time of flight; USPIO = ultrasmall superparamagnetic iron oxide; carotid artery; risk; ultrasound; vascular disorders.
Comment in
-
Letter to the Editor: Contemporary carotid imaging.J Neurosurg. 2016 Jun;124(6):1884. doi: 10.3171/2016.2.JNS16237. Epub 2016 May 6. J Neurosurg. 2016. PMID: 27153170 No abstract available.
Similar articles
-
Plaque vulnerability in patients with high- and moderate-grade carotid stenosis - comparison of plaque features on MRI with histopathological findings.Swiss Med Wkly. 2020 Feb 17;150:w20174. doi: 10.4414/smw.2020.20174. eCollection 2020 Feb 10. Swiss Med Wkly. 2020. PMID: 32065837
-
MR imaging of vulnerable carotid plaque.Cardiovasc Diagn Ther. 2020 Aug;10(4):1019-1031. doi: 10.21037/cdt.2020.03.12. Cardiovasc Diagn Ther. 2020. PMID: 32968658 Free PMC article. Review.
-
Validity of dual MRI and F-FDG PET imaging in predicting vulnerable and inflamed carotid plaque.Cerebrovasc Dis. 2013;35(4):370-7. doi: 10.1159/000348846. Epub 2013 Apr 30. Cerebrovasc Dis. 2013. PMID: 23635390
-
Investigating the Association of Carotid Atherosclerotic Plaque MRI Features and Silent Stroke After Carotid Endarterectomy.J Magn Reson Imaging. 2024 Jul;60(1):138-149. doi: 10.1002/jmri.29115. Epub 2023 Nov 29. J Magn Reson Imaging. 2024. PMID: 38018669
-
[Dual source computed tomography in analysis of significance and morphology carotid plaques].Przegl Lek. 2013;70(3):118-22. Przegl Lek. 2013. PMID: 24003664 Review. Polish.
Cited by
-
Machine learning-directed electrical impedance tomography to predict metabolically vulnerable plaques.Bioeng Transl Med. 2023 Oct 20;9(1):e10616. doi: 10.1002/btm2.10616. eCollection 2024 Jan. Bioeng Transl Med. 2023. PMID: 38193119 Free PMC article.
-
Modifiable Factors Leading to Increased Length of Stay after Carotid Endarterectomy.Ann Vasc Surg. 2017 Feb;39:195-203. doi: 10.1016/j.avsg.2016.05.126. Epub 2016 Aug 20. Ann Vasc Surg. 2017. PMID: 27554691 Free PMC article.
-
Carotid artery endarterectomy in patients with symptomatic non-stenotic carotid artery disease.Stroke Vasc Neurol. 2022 Jun;7(3):251-257. doi: 10.1136/svn-2021-000939. Epub 2022 Mar 3. Stroke Vasc Neurol. 2022. PMID: 35241631 Free PMC article.
-
Spectral Photon-Counting CT Imaging of Gold Nanoparticle Labelled Monocytes for Detection of Atherosclerosis: A Preclinical Study.Diagnostics (Basel). 2023 Jan 29;13(3):499. doi: 10.3390/diagnostics13030499. Diagnostics (Basel). 2023. PMID: 36766602 Free PMC article.
-
Association of plaque enhancement on vessel wall MRI and the phosphodiesterase 4D variant with stroke recurrence in patients with symptomatic intracranial atherosclerosis.Neuroradiology. 2022 Sep;64(9):1781-1794. doi: 10.1007/s00234-022-02948-3. Epub 2022 Apr 14. Neuroradiology. 2022. PMID: 35420310
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Other Literature Sources
Miscellaneous