P2‐415: Lower Arterial Blood Flow and Higher Pulsatility Index Are Associated With Neuronal Injury
Year: 2019
Type: article
Study design: Observational Study
Abstract: Alterations to white matter microstructure (WMM) occur in aging and Alzheimer's disease (AD). WMM degeneration, including myelinated axon loss, likely contributes to cognitive decline, however, its causes are incompletely understood. Previous studies suggest microvascular injury and peripheral vascular risk factors contribute to WMM degeneration; however, the impact of large vessel intracranial blood flow is not fully understood. The present study uses 4-D flow MRI and multi-shell DWI data to determine the extent to which altered WMM is associated with macroscopic intracranial blood flow This study included 246 cognitively unimpaired participants (mean age 64.7 (SD = 8.18), 63.4% female, 30.3% APOE-ε4 positive) from the Wisconsin Registry for Alzheimer's Prevention and Wisconsin ADRC Clinical Core. Intracranial 4-D blood flow features (Mean blood flow (mL/sec), and pulsatility index (PI = (Flowmax-Flowmin)/Flowmean) were measured in the posterior cerebral, middle cerebral and internal carotid arteries using Phase Contrast Vastly undersampled Isotropic Projection (PCVIPR) MRI imaging (published in Rivera-Rivera, et al., 2017). WMM measures were determined from multi-shell DWI applying DTI and NODDI modeling to derive: mean diffusivity (MD), fractional anisotropy (FA), orientation dispersion index (ODI) and neurite density index (NDI). DWI metrics for major white matter tracts were extracted using the JHU white matter tractography atlas and averaged to create hemispheric WMM indices. All metrics (4D Flow and DWI) underwent quality control and were excluded from analysis for excessive acquisition artifacts. Cross-sectional linear fixed-effects models were employed including age and sex as covariates. Lower mean blood flow and higher PI in major cerebral arteries were associated with significantly altered left (Figure 1, Table 1) and right (Figure 2, Table 2) WMM, suggesting white matter injury. Effects in the left hemisphere were particularly robust.
Source: Alzheimer s & Dementia
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4233612499