Journal of Marine Medical Society

COMMENTARY
Year
: 2019  |  Volume : 21  |  Issue : 2  |  Page : 138-

Carotid artery plaque evaluation by shear wave elastography


Faiz M H Ahmad, Subrat K Nanda 
 Senior Advisers (Med) and Neurologists, Department of Neurology, Command Hospital (SC), Pune, Maharashtra, India

Correspondence Address:
Col (Prof.) Faiz M H Ahmad
Command Hospital (SC), Pune - 411 040, Maharashtra
India




How to cite this article:
Ahmad FM, Nanda SK. Carotid artery plaque evaluation by shear wave elastography.J Mar Med Soc 2019;21:138-138


How to cite this URL:
Ahmad FM, Nanda SK. Carotid artery plaque evaluation by shear wave elastography. J Mar Med Soc [serial online] 2019 [cited 2020 Aug 6 ];21:138-138
Available from: http://www.marinemedicalsociety.in/text.asp?2019/21/2/138/268623


Full Text



In this issue of the journal, the article “Evaluation of carotid plaque vulnerability using shear-wave elastography: An observational comparative study” by Sivasankar et al.[1] focuses on a novel technique as a tool to study vulnerable plaques in carotid arteries for ischemic stroke.

Stroke remains the second leading cause of morbidity and mortality worldwide.[2] Ischemic strokes contribute by far the greatest burden of all strokes, and carotid artery atherosclerosis is commonly implicated in their causation.[2],[3] Modalities available for the assessment of carotid artery stenosis include duplex ultrasonography, computed tomography (CT), magnetic resonance (MR) angiography, and catheter-related angiography. Of these, the least expensive and most easily accessible modality remains the duplex ultrasonography. In duplex ultrasonography, the degree of carotid stenosis is measured by determining the blood flow velocity at various segments of the vessel, and various criteria have been developed to translate these velocity parameters into clinically useful stenosis cutoff points.[4] In routine clinical practice, carotid ultrasonography and contrast-enhanced CT or MR angiographic studies are utilized to evaluate carotid artery stenosis, proceeding to catheter-related angiography in cases with discrepancy between the above modalities, or when intervention is planned.[5]

However, newer ultrasound modalities such as duplex color Doppler ultrasound with radiofrequency image acquisition can detect the plaque morphology and predict vulnerable plaques by combining the analysis of echogenicity and mechanical properties of the plaques such as translational motion, strain, and shear.[6]

Of these, “shear wave elastography” (SWE) has been evaluated in recent times for the detection of vulnerable plaques.[6] This technique involves the detection of asymmetric distribution of the mechanical stress across the carotid plaque with greater stress proximally as compared to the distal segment. This is measured as “kpa” values, signifying the loss of elasticity.

The authors, in a prospective observational comparative study, have attempted to assess SWE as a marker of plaque vulnerability. They compared thirty cases with stroke and plaques in the carotid arteries with matched controls without stroke.[7] They further studied the plaque characteristics among stroke-afflicted patients and have compared the affected carotid artery with the unaffected side. The cases with stroke had internal carotid artery implicated in 80% compared to the unaffected side in 40% and greater mean length and width of the plaque. Further, they have reported a statistically significant difference in the SWE findings, with lesser stiffness or greater elasticity, i.e., proximal kpa – 32.27 versus 38.15, mid kpa – 32.92 versus 45.77, and distal kpa – 26.57 versus 38.15 in the proximal, mid and distal plaques, respectively.

Thus, this study has elegantly revealed statistically significant differences in the culprit plaques of carotid arteries. This technique has the potential to provide inexpensive, reliable, and reproducible risk stratification for carotid artery atherosclerosis.[8]

References

1Sivasankar R, Singh R, Hashim PI, Soni BK, Patel RK, Bajpai A. Evaluation of carotid plaque vulnerability using shear-wave elastography: An observational comparative study. J Mar Med Soc 2019;21:134-7.
2Murray C, Lopez A. Global Health Statistics: A Compendium of Incidence, Prevalence and Mortality Estimates for Over 200 Conditions. Cambridge, MA: Harvard University Press; 1996.
3Hajat C, Heuschmann PU, Coshall C, Padayachee S, Chambers J, Rudd AG, et al. Incidence of aetiological subtypes of stroke in a multi-ethnic population based study: The South London stroke register. J Neurol Neurosurg Psychiatry 2011;82:527-33.
4Flaherty ML, Kissela B, Khoury JC, Alwell K, Moomaw CJ, Woo D, et al. Carotid artery stenosis as a cause of stroke. Neuroepidemiology 2013;40:36-41.
5Shaalan WE, Wahlgren CM, Desai T, Piano G, Skelly C, Bassiouny HS. Reappraisal of velocity criteria for carotid bulb/internal carotid artery stenosis utilizing high-resolution B-mode ultrasound validated with computed tomography angiography. J Vasc Surg 2008;48:104-12.
6U-King-Im JM, Hollingworth W, Trivedi RA, Cross JJ, Higgins NJ, Graves MJ, et al. Cost-effectiveness of diagnostic strategies prior to carotid endarterectomy. Ann Neurol 2005;58:506-15.
7Gupta A, Baradaran H, Schweitzer AD, Kamel H, Pandya A, Delgado D, et al. Carotid plaque MRI and stroke risk: A systematic review and meta-analysis. Stroke 2013;44:3071-7.
8Lou Z, Yang J, Tang L, Jin Y, Zhang J, Liu C, et al. Shear wave elastography imaging for the features of symptomatic carotid plaques: A feasibility study. J Ultrasound Med 2017;36:1213-23.