title: Quantification of Lipid-Rich Core in Carotid Atherosclerosis Using Magnetic Resonance T2Mapping: Relation to Clinical Presentation.
abstract: The aim of this study was to: 1) provide tissue validation of quantitative T2mapping to measure plaque lipid content; and 2) investigate whether this technique could discern differences in plaque characteristics between symptom-related and non-symptom-related carotid plaques.
  
  
  
  Noninvasive plaque lipid quantification is appealing both for stratification in treatment selection and as a possible predictor of future plaque rupture. However, current cardiovascular magnetic resonance (CMR) methods are insensitive, require a coalesced mass of lipid core, and rely on multicontrast acquisition with contrast media and extensive post-processing.
  
  
  
  Patients scheduled for carotid endarterectomy were recruited for 3-T carotid CMR before surgery. Lipid area was derived from segmented T2maps and compared directly to plaque lipid defined by histology.
  
  
  
  Lipid area (%) on T2mapping and histology showed excellent correlation, both by individual slices (R = 0.85, p < 0.001) and plaque average (R = 0.83, p < 0.001). Lipid area (%) on T2maps was significantly higher in symptomatic compared with asymptomatic plaques (31.5 ± 3.7% vs. 15.8 ± 3.1%; p = 0.005) despite similar degrees of carotid stenosis and only modest difference in plaque volume (128.0 ± 6.0 mm3symptomatic vs. 105.6 ± 9.4 mm3asymptomatic; p = 0.04). Receiver-operating characteristic analysis showed that T2mapping has a good ability to discriminate between symptomatic and asymptomatic plaques with 67% sensitivity and 91% specificity (area under the curve: 0.79; p = 0.012).
  
  
  
  CMR T2mapping distinguishes different plaque components and accurately quantifies plaque lipid content noninvasively. Compared with asymptomatic plaques, greater lipid content was found in symptomatic plaques despite similar degree of luminal stenosis and only modest difference in plaque volumes. This new technique may find a role in determining optimum treatment (e.g., providing an indication for intensive lipid lowering or by informing decisions of stents vs. surgery).
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Chai
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Luca
authors.initials: L
authors.lastname: Biasiolli
authors.affiliation: National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.
authors.forename: Linqing
authors.initials: L
authors.lastname: Li
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alkhalil
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Francesca
authors.initials: F
authors.lastname: Galassi
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Chris
authors.initials: C
authors.lastname: Darby
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Alison W
authors.initials: AW
authors.lastname: Halliday
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Linda
authors.initials: L
authors.lastname: Hands
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Timothy
authors.initials: T
authors.lastname: Magee
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Perkins
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Ed
authors.initials: E
authors.lastname: Sideso
authors.affiliation: Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Ashok
authors.initials: A
authors.lastname: Handa
authors.affiliation: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Jezzard
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Robson
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom. Electronic address: robin.choudhury@cardiov.ox.ac.uk.
authors.forename: Robin P
authors.initials: RP
authors.lastname: Choudhury
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D058070:Asymptomatic Diseases; D002339:Carotid Arteries / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008055:Lipids / Q000032:analysis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012422:Rupture, Spontaneous
chemical_list: D008055:Lipids
keywords: T(2) mapping; atherosclerosis; cardiovascular magnetic resonance; carotid; lipid; plaque