New quantification methods for carotid intraplaque neovascularization in contrast enhanced ultrasound

Carotid intraplaque neovascularization (IPN) has been associated with progressive atherosclerotic disease and plaque vulnerability. Therefore, its accurate quantification might allow early detection of plaque vulnerability. Contrast enhanced ultrasound (CEUS) can detect these small microvessels. To quantify IPN, we developed quantitative methods based on time intensity curve (TIC) and maximum intensity projection (MIP), micro-vascular structure analysis (VSA), and statistical segmentation (SS). Plaque region of interest (ROI) is manually drawn and motion compensation is applied before each analysis. In TIC and MIP, we examine perfusion dynamics and regions within plaques. In VSA, we detect and track contrast spots to examine the microvessel network. In SS, we classify plaque intensities into different components for quantification of IPN. Through an iterative expectation-maximization algorithm, plaque pixels are initially labeled into artifacts, contrast, intermediate, and background class. Next, spatiotemporal and neighborhood information is used to relabel intermediate class pixels, remove artifacts and correct false-contrast. From the applied analyses, we derived several parameters - e.g. MIP based IPN surface area (MIPNSA), MIP based surface ratio (MIPNSR), SS based IPN surface area (SSIPNSA), plaque mean intensity, mean plaque contrast percentage, and number of microvessels (MVN) - and compared them to consensus of visual grading of IPN by two independent physicians. We analyzed 45 carotid arteries with stenosis. To verify if SSIPNSA improves the suppression of artifacts, we analyzed 8 plaques twice, with saturation artifacts included and excluded from the ROI. Five parameters were found to be significantly correlated to visual scoring and may thus have the potential to replace qualitative visual scoring and to measure the degree of carotid IPN. The MIPNSA & SSIPNSA parameters gave the best distinction between visual scores. SSIPNSA proved less sensitive for artifacts than MIPNSA.

[1]  Sasan Partovi,et al.  Correlation of carotid artery atherosclerotic lesion echogenicity and severity at standard US with intraplaque neovascularization detected at contrast-enhanced US. , 2011, Radiology.

[2]  Ankur Thapar,et al.  Dose-dependent artifact in the far wall of the carotid artery at dynamic contrast-enhanced US. , 2012, Radiology.

[3]  Wouter Peeters,et al.  Composition of Carotid Atherosclerotic Plaque Is Associated With Cardiovascular Outcome: A Prognostic Study , 2010, Circulation.

[4]  Dan Adam,et al.  Carotid plaque vulnerability: quantification of neovascularization on contrast-enhanced ultrasound with histopathologic correlation. , 2011, AJR. American journal of roentgenology.

[5]  Steven B. Feinstein,et al.  Vasa Vasorum and Plaque Neovascularization on Contrast-Enhanced Carotid Ultrasound Imaging Correlates With Cardiovascular Disease and Past Cardiovascular Events , 2010, Stroke.

[6]  Roberto Chiesa,et al.  Contrast-enhanced ultrasound imaging of intraplaque neovascularization in carotid arteries: correlation with histology and plaque echogenicity. , 2008, Journal of the American College of Cardiology.

[7]  Ji-fei Tang,et al.  Contrast‐enhanced sonographic characteristics of neovascularization in carotid atherosclerotic plaques , 2008, Journal of clinical ultrasound : JCU.

[8]  Nico de Jong,et al.  Statistical segmentation of carotid plaque neovascularization , 2013, Medical Imaging.

[9]  M. Eliasziw,et al.  the North American Symptomatic Carotid Endarterectomy Trial (NASCET) Collaborators , 2002 .

[10]  Roberto Chiesa,et al.  Contrast-enhanced ultrasound imaging of periadventitial vasa vasorum in human carotid arteries. , 2009, European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology.

[11]  Nico de Jong,et al.  Far-wall pseudoenhancement during contrast-enhanced ultrasound of the carotid arteries: clinical description and in vitro reproduction. , 2012, Ultrasound in medicine & biology.

[12]  Folkert J Ten Cate,et al.  Contrast-enhanced ultrasound for imaging vasa vasorum: comparison with histopathology in a swine model of atherosclerosis. , 2010, European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology.

[13]  Ioannis Kakadiaris,et al.  In-vivo imaging of carotid plaque neoangiogenesis with contrast-enhanced harmonic ultrasound. , 2009, International journal of cardiology.

[14]  Nico de Jong,et al.  Quantitative analysis of ultrasound contrast flow behavior in carotid plaque neovasculature. , 2012, Ultrasound in medicine & biology.

[15]  E. Sijbrands,et al.  Current status and future developments of contrast-enhanced ultrasound of carotid atherosclerosis. , 2013, Journal of vascular surgery.

[16]  Zeynettin Akkus,et al.  Carotid Intraplaque Neovascularization Quantification Software (CINQS) , 2015, IEEE Journal of Biomedical and Health Informatics.

[17]  Christopher B. Kendall,et al.  Use of carotid ultrasound to identify subclinical vascular disease and evaluate cardiovascular disease risk: a consensus statement from the American Society of Echocardiography Carotid Intima-Media Thickness Task Force. Endorsed by the Society for Vascular Medicine. , 2008, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[18]  Elena Bonanno,et al.  Extracranial thrombotically active carotid plaque as a risk factor for ischemic stroke. , 2004, JAMA.

[19]  S. Feinstein,et al.  Contrast ultrasound imaging of the carotid artery vasa vasorum and atherosclerotic plaque neovascularization. , 2006, Journal of the American College of Cardiology.

[20]  Antonio Colombo,et al.  Terminology for high-risk and vulnerable coronary artery plaques. Report of a meeting on the vulnerable plaque, June 17 and 18, 2003, Santorini, Greece. , 2004, European heart journal.

[21]  Nico de Jong,et al.  Motion compensation method using dynamic programming for quantification of neovascularization in carotid atherosclerotic plaques with contrast enhanced ultrasound (CEUS) , 2012, Medical Imaging.

[22]  Youbin Deng,et al.  Correlation of carotid plaque neovascularization detected by using contrast-enhanced US with clinical symptoms. , 2009, Radiology.

[23]  E. Boerwinkle,et al.  From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I. , 2003, Circulation.

[24]  Gieri Cathomas,et al.  Arterial Neovascularization and Inflammation in Vulnerable Patients: Early and Late Signs of Symptomatic Atherosclerosis , 2004, Circulation.

[25]  Steven B. Feinstein,et al.  Contrast-enhanced ultrasound imaging of atherosclerotic carotid plaque neovascularization: a new surrogate marker of atherosclerosis? , 2007, Vascular medicine.

[26]  F. D'Astous.  Ultrasound in Medicine and Biology Prize. , 1989, Ultrasound in medicine & biology.

[27]  V. Hachinski,et al.  The North American Symptomatic Carotid Endarterectomy Trial : surgical results in 1415 patients. , 1999, Stroke.

[28]  Jean-Baptiste Michel,et al.  Intraplaque haemorrhages as the trigger of plaque vulnerability , 2011, European heart journal.

[29]  J. Hudson.  Quantification of Blood Flow Using Ultrasound Contrast Agents , 2011 .

[30]  S. A. Gutnikov,et al.  Reanalysis of the Final Results of the European Carotid Surgery Trial , 2003, Stroke.

[31]  N de Jong,et al.  Counter-propagating wave interaction for contrast-enhanced ultrasound imaging , 2012, Physics in medicine and biology.