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Vulnerable atherosclerotic plaques in the carotid arteries are at greater risk of causing ischemic cerebrovascular events. One of the major characteristics of vulnerable plaques is intraplaque hemorrhage (IPH), which is associated with an increased risk of plaque rupture. The presence or absence of HIP plays a key role in stratifying the risk of future events in patients with carotid atherosclerosis. Although carotid endarterectomy or carotid stenting helps prevent strokes, it can lead to intraoperative embolic complications, particularly when the plaques contain numerous vulnerable components. Therefore, a method for characterizing intraplaque components is needed to predict cerebrovascular ischemic events and perioperative complications.
This internship is part of the CARPUS study. The objective of this study is to identify plaques at high risk for stroke by detecting neovascularization and intraplaque hemorrhage using ultrasound localization microscopy [1] to assess the presence of new blood vessels and ultrasound spectroscopy to determine the presence and extent of intraplaque hemorrhage. This study requires the recruitment of 15 patients requiring surgery who will undergo two scheduled ultrasound and MRI examinations. The primary objective is to assess the presence of neovascularization in the plaques. A comparison of the presence of neovessels and intraplaque hemorrhage as assessed by ultrasound versus histology is planned for the plaques after surgery. The second objective of this study concerns the possibility of assessing the presence of intraplaque hemorrhage using ultrasound spectroscopy. To this end, areas of intraplaque hemorrhage will be extracted from the MRI scans of the plaques. To date, 3D ultrasound imaging has been performed on 9 patients.
The objective of the internship will be to investigate the presence of neovascularization in the images of the plaques. To this end, 5-minute 3D scans using ultrasound contrast agents were performed on the 9 patients. The technique that will be used, ultrasound localization microscopy, involves several steps that will need to be investigated (image formation, tissue filtering methods, and microbubble detection and tracking). The presence of new blood vessels can be confirmed through histological analysis of the patients’ plaques. An example of initial post-processing to restore blood flow is shown in Figure 1. Depending on the progress of the internship, the candidate may also explore post-processing of the images using ultrasound spectroscopy and the assessment of intraplaque hemorrhage.
[1] Couture O, Hingot V, Heiles B, Muleki-Seya P, Tanter M. Ultrasound Localization Microscopy and Super-Resolution: A State of the Art. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 2018;65:1304–20. https://doi.org/10.1109/TUFFC.2018.2850811.
Internship Details and Candidate Profile:
This internship will take place at the CREATIS laboratory within the Ultrasound Imaging team (University of Lyon 1, Villeurbanne) in collaboration with Dr. Ariane Blerot, a vascular physician at Croix Rousse Hospital.
The candidate should have a degree in engineering or equivalent, with a specialization in signal processing for medical imaging. Experience in ultrasound imaging is preferred. Proficiency in MATLAB is also required.
Supervision:
Pauline MULEKI SEYA, pauline.muleki-seya@creatis.insa-lyon.fr
Gwendal DUBOIS, gwendal.dubois@creatis.insa-lyon.fr
How to candidate ? Please send your resume, transcript, and cover letter to pauline.muleki-seya@creatis.insa-lyon.fr