PT - JOURNAL ARTICLE AU - Pierre Brugières AU - Philippe Thomas AU - Anne Maraval AU - Hassan Hosseini AU - Catherine Combes AU - Abdallah Chafiq AU - Lucile Ruel AU - Stéphane Breil AU - Marc Peschanski AU - André Gaston TI - Water Diffusion Compartmentation at High <em>b</em> Values in Ischemic Human Brain DP - 2004 May 01 TA - American Journal of Neuroradiology PG - 692--698 VI - 25 IP - 5 4099 - http://www.ajnr.org/content/25/5/692.short 4100 - http://www.ajnr.org/content/25/5/692.full SO - Am. J. Neuroradiol.2004 May 01; 25 AB - BACKGROUND AND PURPOSE: We studied the evolution of brain water compartments during the early stage of ischemic stroke.METHODS: Diffusion-weighted imaging was performed at 1.5 T in 10 volunteers and 14 patients with stroke. We used a single-shot echo-planar technique with 11 b values of 0–5000 s/mm2. Regions of interest were selected in the white matter (WM) and striatum of the volunteers and in the ischemic core of the patients. Measurements were fitted on the basis of a biexponential decay with the b factor as follows: S(b) = S(0)[(fslow × exp(−b × ADCslow) + (ffast × exp(−b ×ADCfast)] where S(b) is the signal intensity in the presence of a diffusion gradient, S(0) is the signal intensity without diffusion sensitization, ADCslow and ADCfast are the respective apparent diffusion coefficients (ADCs) of slow diffusing compartments (SDCs) and fast diffusing compartments (FDCs), and fslow and ffast the respective contributions to the signal intensity of SDC and FDC.RESULTS: In healthy subjects, FDC represents 74.3 ± 3.1% of brain water, with ADCfast = (124.6 ± 12.0) × 10−5 mm2/s and ADCslow = (15.5 ± 3.9) × 10−5 mm2/s. In stroke, decreased FDC (49.1% ± 10.9%; P = 1.05 ×10−5) and increased ADCslow ([22.4 ± 8.1] × 10−5 mm2/s; P = 8.07 × 10−3) were observed, but ADCfast was not significantly changed ([135.6 ± 25.7] × 10 −5 mm2/s; P = .151).CONCLUSION: The restricted diffusion observed in the early stroke is mainly related to a redistribution of water from the FDC to the SDC.