Barriers and facilitators to clinical adoption of 3D ultrasound for volumetric stenosis measurement for grading carotid artery stenosis (CAS)

Carotid artery stenosis is a major contributor to ischaemic stroke, a leading cause of mortality and disability. Current diagnostic practices rely on the NASCET (North American Symptomatic Carotid Endarterectomy Trial) criteria, which use 2D ultrasound to compare the narrowest artery segment to a distal, disease-free section1. While effective, this method is limited by underrepresenting key plaque features such as volume, surface irregularities, and ulceration, which are key in assessing stroke risk2. Our solution replaces conventional 2D with 3D ultrasound probe into routine diagnostic workflow. This advanced system offers real-time, high-resolution, and volumetric assessment of carotid plaques, capturing essential details that are often missed by 2D imaging3. The integration of 3D ultrasound allows for a holistic assessment of plaque morphology, giving clinicians a fuller understanding of plaque vulnerability. This comprehensive visualisation enables a more precise grading of stenosis and better identification of high-risk plaques. By reducing diagnostic operator-dependent variability and improving reproducibility, the technology empowers clinicians to make more confident, timely decisions regarding carotid endarterectomy or stenting, ultimately enhancing stroke prevention strategies4. The 3D ultrasound probe is at Technology Readiness Level (TRL) 3-4, with a working proof-of-concept in controlled environments. Preliminary studies using vascular models demonstrated superior imaging resolution and more accurate stenosis measurements compared to traditional 2D ultrasound2. Importantly, the 3D system has shown potential to reduce operator variability, an ongoing challenge with 2D ultrasound, ensuring more consistent diagnostic results across clinical settings3. The next critical step is clinical validation in a real-world setting. Our proposed study will compare the diagnostic accuracy and reproducibility of 3D ultrasound with current 2D standards in patients with carotid artery stenosis. The central research question is: Can 3D ultrasound provide a more accurate and reproducible diagnosis of carotid stenosis, leading to better clinical decision-making and stroke prevention? This project addresses the core objective of the i4i FAST call by developing an innovative 3D ultrasound technology that targets a critical clinical need—improving the diagnostic accuracy of carotid artery stenosis, a leading cause of stroke1. By transitioning from 2D to 3D imaging, our solution provides enhanced precision in stroke risk assessment, facilitating earlier and more effective interventions. Additionally, this project supports i4i s goal of de-risking technologies for NHS adoption. The 3D probe offers a scalable, non-invasive, and cost-effective solution that integrates easily into existing diagnostic workflows, making it highly practical for widespread clinical use4. Its ability to provide actionable, reproducible data with minimal disruption to current practices underscores its potential for transforming clinical pathways. We have engaged with clinicians and patients to inform this project. Vascular scientists and surgeons highlighted the limitations of 2D imaging, particularly its variability in visualising complex plaque features. Clinicians expressed that the 3D probe improves diagnostic confidence by providing clearer, more detailed images. Patients, especially those with a history of carotid disease, voiced concerns about the inconsistency of 2D ultrasound results and supported the development of a more reliable diagnostic tool. Their input has been crucial in refining the study design and ensuring the 3D probe addresses real-world clinical needs.