MRI Assessment of Ischemic Lesion Evolution within White and Gray Matter

TY - JOUR

T1 - MRI Assessment of Ischemic Lesion Evolution within White and Gray Matter

AU - Berner, Lise-Prune

AU - Cho, Tae-Hee

AU - Haesebaert, Julie

AU - Bouvier, Julien

AU - Wiart, Marlène

AU - Hjort, Niels

AU - Klærke Mikkelsen, Irene

AU - Derex, Laurent

AU - Thomalla, Götz

AU - Pedraza, Salvador

AU - Østergaard, Leif

AU - Baron, Jean-Claude

AU - Nighoghossian, Norbert

AU - Berthezène, Yves

N1 - © 2016 S. Karger AG, Basel.

PY - 2016/2/12

Y1 - 2016/2/12

N2 - BACKGROUND: In acute ischemic stroke (AIS), gray matter (GM) and white matter (WM) have different vulnerabilities to ischemia. Thus, we compared the evolution of ischemic lesions within WM and GM using MRI.METHODS: From a European multicenter prospective database (I-KNOW), available T1-weighted images were identified for 50 patients presenting with an anterior AIS and a perfusion weighted imaging (PWI)/diffusion weighted imaging (DWI) mismatch ratio of 1.2 or more. Six lesion compartments were outlined: initial DWI (b = 1,000 s/mm2) lesion, initial PWI-DWI mismatch (Tmax >4 s and DWI-negative), final infarct mapped on 1-month fluid-attenuated inversion recovery (FLAIR) imaging, lesion growth between acute DWI and 1-month FLAIR, DWI lesion reversal at 1 month and salvaged mismatch. The WM and GM were segmented on T1-weighted images, and all images were co-registered within subjects to the baseline MRI. WM and GM proportions were calculated for each compartment.RESULTS: Fifty patients were eligible for the study. Median delay between symptom onset and baseline MRI was 140 min. The percentage of WM was significantly greater in the following compartments: initial mismatch (52.5 vs. 47.5%, p = 0.003), final infarct (56.7 vs. 43.3%, p < 0.001) and lesion growth (58.9 vs. 41.2%, p < 0.001). No significant difference was found between GM and WM percentages within the initial DWI lesion, DWI reversal and salvaged mismatch compartments.CONCLUSIONS: Ischemic lesions may extend preferentially within the WM. Specific therapeutic strategies targeting WM ischemic processes may deserve further investigation.

AB - BACKGROUND: In acute ischemic stroke (AIS), gray matter (GM) and white matter (WM) have different vulnerabilities to ischemia. Thus, we compared the evolution of ischemic lesions within WM and GM using MRI.METHODS: From a European multicenter prospective database (I-KNOW), available T1-weighted images were identified for 50 patients presenting with an anterior AIS and a perfusion weighted imaging (PWI)/diffusion weighted imaging (DWI) mismatch ratio of 1.2 or more. Six lesion compartments were outlined: initial DWI (b = 1,000 s/mm2) lesion, initial PWI-DWI mismatch (Tmax >4 s and DWI-negative), final infarct mapped on 1-month fluid-attenuated inversion recovery (FLAIR) imaging, lesion growth between acute DWI and 1-month FLAIR, DWI lesion reversal at 1 month and salvaged mismatch. The WM and GM were segmented on T1-weighted images, and all images were co-registered within subjects to the baseline MRI. WM and GM proportions were calculated for each compartment.RESULTS: Fifty patients were eligible for the study. Median delay between symptom onset and baseline MRI was 140 min. The percentage of WM was significantly greater in the following compartments: initial mismatch (52.5 vs. 47.5%, p = 0.003), final infarct (56.7 vs. 43.3%, p < 0.001) and lesion growth (58.9 vs. 41.2%, p < 0.001). No significant difference was found between GM and WM percentages within the initial DWI lesion, DWI reversal and salvaged mismatch compartments.CONCLUSIONS: Ischemic lesions may extend preferentially within the WM. Specific therapeutic strategies targeting WM ischemic processes may deserve further investigation.

U2 - 10.1159/000444131

DO - 10.1159/000444131

M3 - SCORING: Journal article

C2 - 26867026

VL - 41

SP - 291

EP - 297

JO - CEREBROVASC DIS

JF - CEREBROVASC DIS

SN - 1015-9770

IS - 5-6

ER -