title: Characterization of intracranial atherosclerotic stenosis using high-resolution MRI study--rationale and design.
abstract: BACKGROUND
  Intracranial atherosclerosis is a leading cause of stroke, but little is known about the composition of the intracranial atherosclerotic lesion and how intracranial plaque morphology is related to the risk of stroke. High-resolution magnetic resonance imaging (HR MRI) has been used in patients with extracranial carotid atherosclerosis as an in vivo tool to identify, with high-interrater agreement, histologically defined plaque components (i.e., intraplaque hemorrhage, fibrous cap, and lipid core), which have been shown to be predictors of recurrent stroke. With careful imaging the components of atherosclerotic plaque can be visualized in the intracranial arteries using HR MRI, but there are no reports of reproducibility or interrater reliability.
  
  
  METHODS
  The Characterization of intracranial atherosclerotic stenosis using high-resolution MRI (CHIASM) study is a single-center NIH-funded prospective observational study, to (1) demonstrate high -interrater agreement for identifying intracranial plaque components on HR MRI, (2) determine the frequency of these components in symptomatic versus asymptomatic plaques, and (3) estimate the 1-year rate of stroke in the territory of high-risk plaque components. CHIASM will recruit 90 patients with 50-99% intracranial atherosclerosis to undergo HRMRI of the intracranial artery plaque at enrollment and 1-year follow-up. Both symptomatic and asymptomatic subjects will be recruited.
  
  
  CONCLUSIONS
  Determination of good interrater reliability is an important first step in the development of HR MRI as a tool to predict risk in patients with intracranial atherosclerosis. This study will inform the design of future multicenter studies to determine the prevalence and prognosis of intracranial atherosclerotic plaque components. Such studies could lead to new understanding of the pathophysiological mechanisms of cerebral ischemia in patients with atherosclerotic intracranial stenosis, improvements in risk stratification, and potentially to new treatments of this common and serious disease.
authors.affiliation: Department of Neurology Medical University of South Carolina Charleston South Carolina.
authors.forename: Tanya N
authors.initials: TN
authors.lastname: Turan
authors.affiliation: Department of Neurology Medical University of South Carolina Charleston South Carolina.
authors.forename: Todd
authors.initials: T
authors.lastname: LeMatty
authors.affiliation: Department of Public Health Sciences Medical University of South Carolina Charleston South Carolina.
authors.forename: Renee
authors.initials: R
authors.lastname: Martin
authors.affiliation: Department of Neurology Medical University of South Carolina Charleston South Carolina.
authors.forename: Marc I
authors.initials: MI
authors.lastname: Chimowitz
authors.affiliation: Department of Radiology and Radiological Sciences Medical University of South Carolina Charleston South Carolina.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Rumboldt
authors.affiliation: Department of Radiology and Radiological Sciences Medical University of South Carolina Charleston South Carolina.
authors.forename: M Vittoria
authors.initials: MV
authors.lastname: Spampinato
authors.affiliation: Department of Radiology and Radiological Sciences Medical University of South Carolina Charleston South Carolina.
authors.forename: Seth
authors.initials: S
authors.lastname: Stalcup
authors.affiliation: Department of Neurology Medical University of South Carolina Charleston South Carolina.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Adams
authors.affiliation: Department of Radiology and Radiological Sciences Medical University of South Carolina Charleston South Carolina.
authors.forename: Truman
authors.initials: T
authors.lastname: Brown
mesh_terms: D001921:Brain / Q000473:pathology*; D003251:Constriction, Pathologic / Q000145:classification / Q000175:diagnosis / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D002537:Intracranial Arteriosclerosis / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058226:Plaque, Atherosclerotic / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012107:Research Design; D012306:Risk; D020521:Stroke / Q000517:prevention & control
keywords: Atherosclerotic plaque pathology; high‐resolution MRI; intracranial atherosclerosis; stroke