The differential relationship between white matter cerebrovascular perfusion and microstructure between normal

Donghoon Kim1,2,3, Sarah Yoon2, Timothy M Hughes4

  • 1Department of Biomedical Engineering, University of California, Davis, Davis, CA, USA.

Insights

Mild cognitive impairment (MCI) is linked to altered white matter perfusion and microstructure. Arterial transit time (ATT) and intracellular volume fraction (ICVF) are interconnected in MCI, with cerebrovascular reactivity (CVR) as an independent biomarker.

Area of Science:

  • Neuroimaging
  • Cerebrovascular Health
  • White Matter Integrity

Background:

  • Mild cognitive impairment (MCI) is associated with cerebrovascular perfusion and microstructural changes.
  • The interplay between cerebrovascular perfusion and white matter microstructure in normal-appearing white matter (NAWM) is not well understood.

Purpose of the Study:

  • To explore the distinct associations between white matter cerebrovascular perfusion and microstructure in individuals with normal cognition (NC) versus MCI.
  • To utilize multiple magnetic resonance imaging (MRI) metrics within NAWM to investigate these relationships.

Main Methods:

  • Compared 24 MCI and 55 NC participants using voxel-wise analyses in NAWM.
  • Assessed cerebrovascular reactivity (CVR), cerebral blood flow, arterial transit time (ATT), and intracellular volume fraction (ICVF).
  • Adjusted models for vascular risk factors like hypertension, glycemic status, and APOE ε4 allele presence.

Main Results:

  • MCI participants showed reduced CVR, prolonged ATT, and lower ICVF in NAWM.
  • A negative correlation between ATT and ICVF was observed in MCI-affected brain regions.
  • CVR was identified as an independent imaging biomarker in MCI.

Conclusions:

  • Impaired ATT and ICVF in NAWM are closely linked in MCI.
  • CVR functions as a standalone imaging biomarker for MCI.
  • Further research is needed to elucidate the intrinsic connection between ATT and ICVF in NAWM.