Comparison of cerebral blood flow and structural penumbras in relation to white matter hyperintensities: A multi-modal magnetic resonance imaging study.
Normal-appearing white matter (NAWM) surrounding WMHs is associated with decreased structural integrity and perfusion, increased risk of WMH growth, and is referred to as the WMH penumbra. Studies comparing structural and cerebral blood flow (CBF) penumbras within the same individuals are lacking, however, and would facilitate our understanding of mechanisms resulting in WM damage. This study aimed to compare both CBF and structural WMH penumbras in non-demented aging. Eighty-two elderly volunteers underwent 3T-MRI including fluid attenuated inversion recovery (FLAIR), pulsed arterial spin labeling and diffusion tensor imaging (DTI). A NAWM layer mask was generated for periventricular and deep WMHs. Mean CBF, DTI-fractional anisotropy (DTI-FA), DTI-mean diffusivity (DTI-MD) and FLAIR intensity for WMHs and its corresponding NAWM layer masks were computed and compared against its mean within total brain NAWM using mixed effects models. For both periventricular and deep WMHs, DTI-FA, DTI-MD and FLAIR intensity changes extended 2-9 mm surrounding WMHs (p ≤ 0.05), while CBF changes extended 13-14 mm (p ≤ 0.05). The CBF penumbra is more extensive than structural penumbras in relation to WMHs and includes WM tissue both with and without microstructural changes. Findings implicate CBF as a potential target for the prevention of both micro and macro structural WM damage.
Department of Neurology, Oregon Health & Science University, Portland, USA promjuny@ohsu.edu.
Nutta-On
NO
Promjunyakul
Department of Neurology, Oregon Health & Science University, Portland, USA.
David L
DL
Lahna
Department of Neurology, Oregon Health & Science University, Portland, USA Department of Neurology, Veterans Affairs Medical Center, Portland, USA.
Jeffrey A
JA
Kaye
Department of Neurology, Oregon Health & Science University, Portland, USA.
Hiroko H
HH
Dodge
Department of Neurology, Oregon Health & Science University, Portland, USA Department of Neurology, Veterans Affairs Medical Center, Portland, USA.
Deniz
D
Erten-Lyons
Department of Neurology, Oregon Health & Science University, Portland, USA Advanced Imaging Research Center, Oregon Health & Science University, Portland, USA.
William D
WD
Rooney
Department of Neurology, Oregon Health & Science University, Portland, USA Department of Neurology, Veterans Affairs Medical Center, Portland, USA.
Lisa C
LC
Silbert
D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation / Q000502:physiology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013113:Spin Labels; D066127:White Matter / Q000000981:diagnostic imaging / Q000293:injuries / Q000473:pathology*
D013113:Spin Labels
Arterial spin labeling; aging; cerebral blood flow; diffusion tensor imaging; magnetic resonance imaging; vascular cognitive impairment