Comprehensive analysis of early fractional anisotropy changes in acute ischemic stroke

TY - JOUR

T1 - Comprehensive analysis of early fractional anisotropy changes in acute ischemic stroke

AU - Alegiani, Anna Christina

AU - MacLean, Simon

AU - Braass, Hanna

AU - Siemonsen, Susanne

AU - Gerloff, Christian

AU - Fiehler, Jens

AU - Cho, Tae-Hee

AU - Derex, Laurent

AU - Hermier, Marc

AU - Berthezene, Yves

AU - Nighoghossian, Norbert

AU - Thomalla, Götz

PY - 2017

Y1 - 2017

N2 - BACKGROUND AND PURPOSE: Cerebral ischemia leads to a rapid decrease of the apparent diffusion coefficient. For fractional anisotropy both increase and decrease have been reported in acute ischemic stroke. Aim of this study was to characterize early water diffusion changes in a homogenous group of acute stroke patients and to clarify the issue of early fractional anisotropy changes and their relation to time from symptom onset.METHODS: MRI data of patients with acute ischemic stroke examined by diffusion tensor imaging within 8h after symptom were analyzed. We calculated fractional anisotropy, eigenvalues and the isotropic and anisotropic components of the diffusion tensor. The values were calculated as ratios between the ischemic lesion and a mirror region in the unaffected side and correlated with clinical parameters.RESULTS: We included 63 patients: 49% female, mean age 69 ± 14 years, median NIHSS on admission 9 (IQR 4-14). For the whole sample, mean fractional anisotropy was increased (ratio: 1.083 ± 0.168), while all other diffusion parameters were decreased. Both the isotropic and anisotropic component of the diffusion tensor were decreased with a more pronounced decrease of the isotropic component (ratios: isotropic = 0.730 ± 0.106, anisotropic = 0.788 ± 0.127; p<0.001). There was no correlation of fractional anisotropy with time from symptom onset. Looking at individual patients, fractional anisotropy was increased in 70%. There were no differences in clinical characteristics between patients with increased and decreased fractional anisotropy.CONCLUSION: Fractional anisotropy increase in acute stroke results from a more pronounced decrease of the isotropic diffusion component and is not related to time from symptom onset. Thus, fractional anisotropy is not helpful as a surrogate marker of lesion age in the very first hours of stroke.

AB - BACKGROUND AND PURPOSE: Cerebral ischemia leads to a rapid decrease of the apparent diffusion coefficient. For fractional anisotropy both increase and decrease have been reported in acute ischemic stroke. Aim of this study was to characterize early water diffusion changes in a homogenous group of acute stroke patients and to clarify the issue of early fractional anisotropy changes and their relation to time from symptom onset.METHODS: MRI data of patients with acute ischemic stroke examined by diffusion tensor imaging within 8h after symptom were analyzed. We calculated fractional anisotropy, eigenvalues and the isotropic and anisotropic components of the diffusion tensor. The values were calculated as ratios between the ischemic lesion and a mirror region in the unaffected side and correlated with clinical parameters.RESULTS: We included 63 patients: 49% female, mean age 69 ± 14 years, median NIHSS on admission 9 (IQR 4-14). For the whole sample, mean fractional anisotropy was increased (ratio: 1.083 ± 0.168), while all other diffusion parameters were decreased. Both the isotropic and anisotropic component of the diffusion tensor were decreased with a more pronounced decrease of the isotropic component (ratios: isotropic = 0.730 ± 0.106, anisotropic = 0.788 ± 0.127; p<0.001). There was no correlation of fractional anisotropy with time from symptom onset. Looking at individual patients, fractional anisotropy was increased in 70%. There were no differences in clinical characteristics between patients with increased and decreased fractional anisotropy.CONCLUSION: Fractional anisotropy increase in acute stroke results from a more pronounced decrease of the isotropic diffusion component and is not related to time from symptom onset. Thus, fractional anisotropy is not helpful as a surrogate marker of lesion age in the very first hours of stroke.

KW - Acute Disease

KW - Aged

KW - Aged, 80 and over

KW - Anisotropy

KW - Brain Ischemia

KW - Female

KW - Humans

KW - Male

KW - Middle Aged

KW - Stroke

KW - Journal Article

U2 - 10.1371/journal.pone.0188318

DO - 10.1371/journal.pone.0188318

M3 - SCORING: Journal article

C2 - 29190762

VL - 12

SP - e0188318

JO - PLOS ONE

JF - PLOS ONE

SN - 1932-6203

IS - 11

ER -