Figure 1.
Fluid attenuated inversion recovery (FLAIR) images of SVD participants.
Table 1.
Demographic information on the cs-BOLD cohorts.
Figure 2.
Overview of cs-BOLD imaging and the cardiac pulsatility metric.
A) Axial positioning of the critically-sampled BOLD slices; B) Representative cs-BOLD axial slice from an elderly control at time point 1 (maximum tissue type contrast, non steady-state); C) smoothed mean tissue class power spectrum (each bin contains the integrated power within ±0.02 Hz of the central frequency). NB: non-brain voxels (pulsatility present because of EPI ghosting); CSF: cerebrospinal fluid; GM: grey matter; WM: white matter.
Figure 3.
cs-BOLD physiological noise and cardiac pulsatility results.
(A) Mean physiological noise (σphysio) in the NAWM of young controls (YC), elderly controls (EC), and patients with small vessel disease (SVD); (B) mean cardiac pulsatility in the NAWM of YC, EC, and SVD. *: significant after Bonferroni correction for multiple comparisons.
Table 2.
The proportion of participants that showed NAWM was reduced compared to GM or equivalent to its level in terms of (A) σphysio or (B) cardiac pulsatility.
Figure 4.
Illustrative cardiac pulsatility slices.
Top: cardiac pulsatility in three cs-BOLD participants representative of the YC, EC, and SVD cohorts; bottom: NAWM masks (yellow) overlaid on cs-BOLD images for the same participants, WMH mask (red).
Figure 5.
Comparison between white matter hyperintensities (WMH) and normal appearing white matter (NAWM) using (A) physiological noise and (B) cardiac pulsatility metrics.
Figure 6.
Significant age effect on physiological noise in WM in wb-BOLD data (TR = 2s, n = 84, r = 0.27, p<0.01).