{
  "abstract": "Introduction Carotid atherosclerosis remains a major risk factor for stroke in western countries 1. While clinical management typically depends on stenosis severity, stenosis alone often fails to predict stroke risk accurately 2,3. Molecular plaque composition and endothelial cell dysfunction are crucial determinants of plaque progression and cardiovascular events4–6. This study was designed to selectively identify patients with high-risk carotid atherosclerosis by detecting compositional features of high-risk plaques and assessing endothelial (dys)function in a fast, high-resolution, contrast-free MRI session.Methods Building on our previous work, we have implemented an accelerated, 3D free-breathing, motion-corrected iT2 prep-BOOST research sequence on a 3T MR system (MAGNETOM Vida, Siemens Healthineers AG, Forchheim, Germany) for carotid artery imaging. iT2 prep-BOOST allows for simultaneous bright and dark-blood imaging Images were acquired using a 64-channel head and neck matrix coil (Head/Neck 64, Siemens Healthcare) with cardiac synchronisation via peripheral pulse sensor unit to optimise the acquisition parameters. Patients undergoing carotid endarterectomy (CEA) (n=23) were recruited ( figure 1A). The iT2 prep-BOOST sequence was used for carotid plaque imaging at high resolution (0.9 x 0.9mm) and speed (~6 min). Endothelial (dys)function was measured using a phase-contrast MRI protocol before and 120 seconds after a cold-pressor test (CPT). Plaque-to-muscle ratio (SI plaque/SI reference muscle) using the black-blood images and changes in vessel area and blood flow were analysed. Tissue was collected postoperatively to validate the imaging data.Results Results of the proposed simultaneous lumen and vessel wall BOOST sequence are shown for three patients. MR angiography and examples of bright and black-blood images acquired with iT 2 prep-BOOST, show excellent delineation of the carotid artery lumen and vessel wall in all patients (figure 1B). The PMR measured on MRI was higher in plaques presenting with intraplaque haemorrhage as verified by en face tissue inspection (figure 1C). Assessment of endothelial vasomotor response to CPT showed vasocontraction in all three cases (negative % change in area) and reduction or no change in blood flow (negative or close to zero) (figure 1D).Conclusions In this translational study, we demonstrate for the first time that in vivo imaging of both high-risk plaque features and endothelial (dys)function can be assessed in a single MRI session at high resolution and in under 20 minutes. Such a strategy that provides both anatomical and functional assessment of the plaque may enable better stratification of atherosclerosis and selection of patients at risk.References Gupta A, et al. Stroke 2013.Schindler A, et al. JACC Cardiovasc Imaging 2019.Korol RM, et al. Photochem Photobiol 2011.Lovallo W. Psychophysiology 1975.Hays AG, et al. Am J Physiol Heart Circ Physiol 2015.Hays AG, et al. J Am Coll Cardiol 2010;56:1657–1665.",
  "authors": [
    {
      "affiliations": [
        "King’s College London, London, United Kingdom"
      ],
      "name": "Nadia Chaher"
    },
    {
      "affiliations": [
        "Guy’s and St Thomas Hospital, London, United Kingdom"
      ],
      "name": "Darshan Bakri"
    },
    {
      "affiliations": [
        "Siemens Healthcare Limited, Surrey, United Kingdom"
      ],
      "name": "Karl Kunze"
    },
    {
      "affiliations": [
        "Technische Universität München, Munich, Germany"
      ],
      "name": "Ivan kokhanovskyi"
    },
    {
      "affiliations": [
        "King’s College London, London, United Kingdom",
        "Pontificia Universidad Católica de Chile, Santiago, Chile"
      ],
      "name": "Claudia Prieto"
    },
    {
      "affiliations": [
        "King’s College London, London, United Kingdom",
        "Pontificia Universidad Católica de Chile, Santiago, Chile",
        "British Heart Foundation, London, United Kingdom"
      ],
      "name": "René Botnar"
    },
    {
      "affiliations": [
        "King’s College London, London, United Kingdom",
        "Guy’s and St Thomas Hospital, London, United Kingdom"
      ],
      "name": "Prakash Saha"
    },
    {
      "affiliations": [
        "King’s College London, London, United Kingdom",
        "British Heart Foundation, London, United Kingdom"
      ],
      "name": "Alkystis Phinikaridou"
    }
  ],
  "title": "127 Detection of high-risk carotid plaque features and endothelial health in a single, fast and contrast-free MRI scan",
  "uid": "0743c651-0278-527b-bf19-54cf23b7dbeb"
}