title: Vulnerable carotid plaque imaging and histopathology without a dedicated MRI receiver coil.
abstract: Stroke is associated with vulnerable carotid artery plaques showing specific histopathologic features, namely a lipid-rich necrotic core, intraplaque hemorrhage, ulceration, and thin fibrous cap. While ultrasound and computed tomography (CT) can identify carotid plaques and determine the extent of stenosis, magnetic resonance imaging (MRI) provides further information regarding plaque composition and morphology. In this feasibility study, three patients with symptomatic, moderately stenosed plaques were imaged with CT angiography (CTA) and MRI (3T and 1.5T) without a dedicated receiver coil. The patients subsequently underwent carotid endarterectomy with en-bloc excision of the plaque. The CT and MR images were analyzed independently by three neuroradiologists to identify vulnerable plaque features. The images were correlated with the histopathology to confirm the findings. All three patients had one or more vulnerable plaque features on histopathology. MRI allowed for better characterization of these features when compared to CTA. The pre- and post-contrast T1-weighted (T1W) images were most helpful for identifying the lipid-rich necrotic core and thin fibrous cap, while the time of flight-magnetic resonance angiography (TOF-MRA) and contrast-enhanced (CE)-MRA were excellent for detecting plaque hemorrhage and ulceration, respectively. The 3T images showed superior spatial and contrast resolution compared to the 1.5T images for all sequences. By providing direct correlation between imaging and histopathology, this study demonstrates that 3T MRI without a dedicated surface coil is an excellent tool for assessing plaque vulnerability. In smaller hospitals or those with limited resources, it is reasonable to consider conventional MRI for patient risk stratification. Further studies are needed to determine how MRI and plaque vulnerability can be incorporated into routine clinical practice.
authors.affiliation: 2 Ottawa Hospital Research Institute, Faculty of Medicine, University of Ottawa, Canada.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Fitzpatrick
authors.affiliation: 3 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, Canada.
authors.forename: Nadav
authors.initials: N
authors.lastname: Berkovitz
authors.affiliation: 1 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, Ottawa, Canada; and Harvard T. H. Chan School of Public Health, Boston, USA.
authors.forename: Marlise P
authors.initials: MP
authors.lastname: Dos Santos
authors.affiliation: 3 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, Canada.
authors.forename: Nevin
authors.initials: N
authors.lastname: Majeed
authors.affiliation: 3 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, Canada.
authors.forename: Rafael
authors.initials: R
authors.lastname: Glikstein
authors.affiliation: 3 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, Canada.
authors.forename: Santanu
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: 4 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Pathology and Laboratory Medicine, The Ottawa Hospital, University of Ottawa, Canada.
authors.forename: John P
authors.initials: JP
authors.lastname: Veinot
authors.affiliation: 5 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medicine, The Ottawa Hospital, University of Ottawa, Canada.
authors.forename: Grant
authors.initials: G
authors.lastname: Stotts
authors.affiliation: 3 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Berthiaume
authors.affiliation: 3 Ottawa Hospital Research Institute, Brain and Mind Research Institute, Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Chatelain
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
keywords: Stroke; atherosclerotic; carotid; carotid artery disease; carotid stenosis; endarterectomy; plaque