PhD student New ultrasound-based flow imaging for personalized risk assessment of carotid artery stenosis.

Stroke is among the leading causes of death and disability and in 20% of cases caused by rupture of atherosclerotic plaques in the carotid artery wall. Current clinical monitoring and treatment planning for carotid plaques, primarily based on stenosis grade, is insufficient in adequately predicting stroke. Novel measures, that go beyond simple geometrical indications, are required to improve diagnosing the right patients for treatment of carotid stenosis. The aim of this project is to assess the association between ultrasound-based blood flow patterns and parameters and carotid artery plaque rupture risk and disease progression.

A novel, non-invasive, ultrasound-based blood flow imaging technique will be used to acquire and visualize the blood flow in the carotid artery. This new technique is based on ultrafast ultrasound imaging, a new way of imaging which enables imaging of more than 10.000 images per second. If disease risk and progression can be mapped using this new imaging technique, this could aid improved, patient-specific diagnosis, monitoring and treatment planning. This project is a collaboration between the Rijnstate Arnhem and the Radboudumc Nijmegen. Multiple disciplines within both hospitals (Vascular Surgery, Neurology, Pathology) will participate in this collaboration.

As PhD student on this project, you will perform multiple explorative studies aiming at unravelling the relation between local velocity maps and the progression and risk of atherosclerotic plaques in the carotid artery. It will involve both experimental and clinical work and you will get acquainted with different techniques (phantom building, 3D printing, histology, ultrasound examinations, patient recruitment). The impact of various stenosis (degree and geometries) on local blood flow patterns will be studied experimentally, using patient-specific, carotid-mimicking phantoms. After you are trained to perform ultrasound recordings of the carotid artery, you will perform two studies in patients.

The first one, in patients with severe symptomatic carotid stenosis, whose blood flow will be imaged before and after surgical excision of the plaque. Based on morphology of the excised plaque (CT and histology) you will study the association between blood flow patterns and parameters and plaque vulnerability.

The second study will be performed in patients with asymptomatic carotid artery stenosis. In this 2-year follow-up study, you will investigate the association between blood flow and the progression of carotid atherosclerosis. With these studies, we aim to demonstrate the potential of the novel ultrasound-based blood flow imaging technique in the assessment of atherosclerotic plaque rupture and disease progression in the individual patient. The ultimate goal is to improve identification of the right patients for surgical treatment of carotid stenosis.

You will be responsible for co-designing, coördinating and performing the proposed studies, while building upon previous work and developed techniques from participating partners. Furthermore, you are expected to publish your research in highly esteemed scientific journals in the fields of ultrasound imaging, radiology, and/or cardiovascular imaging and present at several scientific conferences. This project will result in a dissertation (PhD degree).

We are looking for a candidate:

• With an MSc in Biomedical Technology, Technical Medicine, or a similar university degree.
• Motivated to perform research with the aim to improve diagnosis, monitoring and treatment planning for patients with carotid atherosclerosis.
• Comfortable and enthusiastic about working in a hospital environment.
• Good experimental skills.
• Good communicative skills.
• Fluent in Dutch (because of patient measurements).
• Capable of working in a multi-disciplinary team.
• Interested in software development for signal processing.
• Previous experience with computer programming (e.g. Matlab).
• Statistical knowledge is a plus.

Fixed-term contract: 4 years.

• An appointment (1 fte) as a PhD student for four years at the Rijnstate Arnhem, starting date: April-June 2021.
• A challenging and versatile job in dynamic environments and enthusiastic research teams.
• Workplace equally distributed over Rijnstate Hospital and Radboudumc.
• Starting salary in FWG 50, 2526,- euro, in accordance to the CAO Ziekenhuizen, analog with the UMC-CAO scale 10A.

Radboudumc

Rijnstate Arnhem
The department of Vascular Surgery of Rijnstate is a clinical department with a strong interest in clinical and translational research. The group is embedded in the department of surgery and orthopedics and there is a close collaboration with the department of (interventional) radiology. There is also a close collaboration with the University of Twente. Arnhem is the capital of the province Gelderland and hosts the HAN University of Applied Sciences and ArtEZ University of the Arts. Being part of the "Stichting Top Klinische Ziekenhuizen", Rijnstate has an emphasis on clinical care, education and research. Vascular care is a focus area of the Rijnstate hospital and there is a close collaboration with the other vascular specialists in the Rijnstate Vascular Center.

Radboudumc Nijmegen
The Medical UltraSound Imaging Center (MUSIC) is an enthusiastic team of talented researchers working on state of the art ultrasound technologies to improve diagnosis in cardio-vascular disease and breast cancer. MUSIC is embedded in the Department of Medical Imaging/Radiology of the Radboudumc which facilitates the translation of the developed technology to clinical practice: more than 150 scientists develop and evaluate novel medical imaging techniques. For utilization of the results MUSIC collaborates with industrial partners like Philips, Siemens, Tomtec, Samsung, and Bracco. Nijmegen is the oldest Dutch city with a rich history and enjoying one of the liveliest city centers in the Netherlands. Radboudumc is a leading academic center for medical science, education and health care with over 8,500 staff members and 3,000 students.