title: Quantifying Intracranial Plaque Permeability with Dynamic Contrast-Enhanced MRI: A Pilot Study.
abstract: Intracranial atherosclerotic disease plaque hyperintensity and/or gadolinium contrast enhancement have been studied as imaging biomarkers of acutely symptomatic ischemic presentations using single static MR imaging measurements. However, the value in modeling the dynamics of intracranial plaque permeability has yet to be evaluated. The purpose of this study was to use dynamic contrast-enhanced MR imaging to quantify the contrast permeability of intracranial atherosclerotic disease plaques in symptomatic patients and to compare these parameters against existing markers of plaque volatility using black-blood MR imaging pulse sequences.
  
  
  
  We performed a prospective study of contrast uptake dynamics in the major intracranial vessels proximal and immediately distal to the circle of Willis using dynamic contrast-enhanced MR imaging, specifically in patients with symptomatic intracranial atherosclerotic disease. Using the Modified Tofts model, we extracted the volume transfer constant (Ktrans) and fractional plasma volume (Vp) parameters from plaque-enhancement curves. Using regression analyses, we compared these parameters against time from symptom onset as well as intraplaque hyperintensity and postcontrast enhancement derived from T1 SPACE, a black-blood MR vessel wall imaging sequence.
  
  
  
  We completed analysis in 10 patients presenting with symptomatic intracranial atherosclerotic disease.Ktransand Vpmeasurements were higher in plaques versus healthy white matter and similar or less than values in the choroid plexus. OnlyKtranscorrelated significantly with time from symptom onset (P= .02). Dynamic contrast-enhanced MR imaging parameters were not found to correlate significantly with intraplaque enhancement or intraplaque hyperintensity (P= .4 andP= .17, respectively).
  
  
  
  ElevatedKtransand Vpvalues found in intracranial atherosclerotic disease plaques versus healthy white matter suggest that dynamic contrast-enhanced MR imaging is a feasible technique for studying vessel wall and plaque characteristics in the proximal intracranial vasculature. Significant correlations betweenKtransand symptom onset, which were not observed on T1 SPACE-derived metrics, suggest thatKtransmay be an independent imaging biomarker of acute and symptom-associated pathologic changes in intracranial atherosclerotic disease plaques.
authors.affiliation: From the College of Medicine (P.V.), University of Illinois, Chicago, Illinois.|Departments of Radiology (P.V., A.H.E., F.S., C.G.C., T.J.C., S.A.A.).|Biomedical Engineering (P.V., C.G.C., T.J.C.).
authors.forename: P
authors.identifier: 0000-0002-3862-2185
authors.initials: P
authors.lastname: Vakil
authors.affiliation: Departments of Radiology (P.V., A.H.E., F.S., C.G.C., T.J.C., S.A.A.).
authors.forename: A H
authors.identifier: 0000-0001-5119-9548
authors.initials: AH
authors.lastname: Elmokadem
authors.affiliation: Departments of Radiology (P.V., A.H.E., F.S., C.G.C., T.J.C., S.A.A.).
authors.forename: F H
authors.identifier: 0000-0002-9048-2538
authors.initials: FH
authors.lastname: Syed
authors.affiliation: Departments of Radiology (P.V., A.H.E., F.S., C.G.C., T.J.C., S.A.A.).|Biomedical Engineering (P.V., C.G.C., T.J.C.).
authors.forename: C G
authors.identifier: 0000-0003-0559-8681
authors.initials: CG
authors.lastname: Cantrell
authors.affiliation: Department of Economics and Decision Sciences (F.H.D.), Western Illinois University, Macomb, Illinois.
authors.forename: F H
authors.identifier: 0000-0002-0990-2436
authors.initials: FH
authors.lastname: Dehkordi
authors.affiliation: Departments of Radiology (P.V., A.H.E., F.S., C.G.C., T.J.C., S.A.A.).|Biomedical Engineering (P.V., C.G.C., T.J.C.).
authors.forename: T J
authors.identifier: 0000-0002-5149-8377
authors.initials: TJ
authors.lastname: Carroll
authors.affiliation: Departments of Radiology (P.V., A.H.E., F.S., C.G.C., T.J.C., S.A.A.) s-ansari@northwestern.edu.|Neurology and Neurological Surgery (S.A.A.), Northwestern University, Chicago, Illinois.
authors.forename: S A
authors.identifier: 0000-0001-8176-4616
authors.initials: SA
authors.lastname: Ansari
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods*; D010539:Permeability; D010865:Pilot Projects; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology*; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D003287:Contrast Media; D005682:Gadolinium