title: Interrogating the Functional Correlates of Collateralization in Patients with Intracranial Stenosis Using Multimodal Hemodynamic Imaging.
abstract: The importance of collateralization for maintaining adequate cerebral perfusion is increasingly recognized. However, measuring collateral flow noninvasively has proved elusive. The aim of this study was to assess correlations among baseline perfusion and arterial transit time artifacts, cerebrovascular reactivity, and the presence of collateral vessels on digital subtraction angiography.
  
  
  
  The relationship between the presence of collateral vessels on arterial spin-labeling MR imaging and DSA was compared with blood oxygen level-dependent MR imaging measures of hypercapnic cerebrovascular reactivity in patients with symptomatic intracranial stenosis (n = 18). DSA maps were reviewed by a neuroradiologist and assigned the following scores: 1, collaterals to the periphery of the ischemic site; 2, complete irrigation of the ischemic bed via collateral flow; and 3, normal antegrade flow. Arterial spin-labeling maps were scored according to the following: 0, low signal; 1, moderate signal with arterial transit artifacts; 2, high signal with arterial transit artifacts; and 3, normal signal.
  
  
  
  In regions with normal-to-high signal on arterial spin-labeling, collateral vessel presence on DSA strongly correlated with declines in cerebrovascular reactivity (as measured on blood oxygen level-dependent MR imaging, P < .001), most notably in patients with nonatherosclerotic disease. There was a trend toward increasing cerebrovascular reactivity with increases in the degree of collateralization on DSA (P = .082).
  
  
  
  Collateral vessels may have fundamentally different vasoreactivity properties from healthy vessels, a finding that is observed most prominently in nonatherosclerotic disease and, to a lesser extent, in atherosclerotic disease.
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: B A
authors.identifier: 0000-0003-0844-2500
authors.initials: BA
authors.lastname: Roach
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.) Neurology (M.J.D.) Psychiatry (M.J.D.) mj.donahue@vanderbilt.edu.
authors.forename: M J
authors.identifier: 0000-0002-4123-9275
authors.initials: MJ
authors.lastname: Donahue
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: L T
authors.identifier: 0000-0003-2939-3875
authors.initials: LT
authors.lastname: Davis
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: C C
authors.identifier: 0000-0001-7906-7942
authors.initials: CC
authors.lastname: Faraco
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: D
authors.identifier: 0000-0002-4920-3592
authors.initials: D
authors.lastname: Arteaga
authors.affiliation: the Vanderbilt Center for Quantitative Sciences (S.-C.C.), Vanderbilt Medical Center, Nashville, Tennessee.
authors.forename: S-C
authors.identifier: 0000-0002-5574-1434
authors.initials: SC
authors.lastname: Chen
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: T R
authors.identifier: 0000-0003-3670-8206
authors.initials: TR
authors.lastname: Ladner
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: A O
authors.identifier: 0000-0003-0305-3098
authors.initials: AO
authors.lastname: Scott
authors.affiliation: From the Departments of Radiology and Radiological Sciences (B.A.R., M.J.D., L.T.D., C.C.F., D.A., T.R.L., A.O.S., M.K.S.).
authors.forename: M K
authors.identifier: 0000-0002-3016-5821
authors.initials: MK
authors.lastname: Strother
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D003097:Collateral Circulation; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*