title: Associations between total cerebral blood flow and age related changes of the brain.
abstract: OBJECTIVE
  Although total cerebral blood flow (tCBF) is known to be related to age, less is known regarding the associations between tCBF and the morphologic changes of the brain accompanying cerebral aging. The purpose of this study was to investigate whether total cerebral blood flow (tCBF) is related to white matter hyperintensity (WMH) volume and/or cerebral atrophy. Furthermore, we investigate whether tCBF should be expressed in mL/min, as was done in all previous MR studies, or in mL/100 mL/min, which yielded good results in precious SPECT, PET and perfusion MRI studies investigating regional cerebral blood flow.
  
  
  METHODS
  Patients were included from the nested MRI sub-study of the PROSPER study. Dual fast spin echo and FLAIR images were obtained in all patients. In addition, single slice phase contrast MR angiography was used for flow measurements in the internal carotids and vertebral arteries. tCBF was expressed in both mL/min and mL/100 mL/min.
  
  
  RESULTS
  We found a significant correlation between tCBF in mL/min and both age (r = -.124; p = p<or=.001) and parenchymal volume (r = 0.430; p<or=.001). We found no association between tCBF in mL/min and %-atrophy (r = -.077; p = .103) or total WMH volume (r = -.069; p = .148). When tCBF was expressed in mL/100 mL/min the correlation between tCBF and age was no longer found (r = -.001; p = .985). Multivariate regression analyses corrected for age showed a significant correlation between tCBF in mL/100 mL/min and WMH volume (r = -.106; p = .044). No significant association between tCBF in mL/100 mL/min and %-atrophy was found.
  
  
  CONCLUSIONS
  From this study we conclude that, when evaluating tCBF alterations due to various pathologies, tCBF should in mL/100 mL/min instead of mL/min. Furthermore, changes or differences in WMH volume should be accounted for.
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands. A.C.G.M.van_Es@LUMC.nl
authors.forename: Adriaan C G M
authors.initials: AC
authors.lastname: van Es
authors.forename: Jeroen
authors.initials: J
authors.lastname: van der Grond
authors.forename: V Hester
authors.initials: VH
authors.lastname: ten Dam
authors.forename: Anton J M
authors.initials: AJ
authors.lastname: de Craen
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Blauw
authors.forename: Rudi G J
authors.initials: RG
authors.lastname: Westendorp
authors.forename: Faiza
authors.initials: F
authors.lastname: Admiraal-Behloul
authors.forename: Mark A
authors.initials: MA
authors.lastname: van Buchem
mesh_terms: D000368:Aged; D000375:Aging; D001284:Atrophy; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D002339:Carotid Arteries / Q000473:pathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014711:Vertebral Artery / Q000473:pathology