TY - JOUR
T1 - Biexponential diffusion attenuation in various states of brain tissue
T2 - Implications for diffusion-weighted imaging
AU - Niendorf, Thoralf
AU - Dijkhuizen, Rick M.
AU - Norris, David G.
AU - Van Lookeren Campagne, Menno
AU - Nicolay, Klaas
PY - 1996/12
Y1 - 1996/12
N2 - Diffusion-weighted single voxel experiments conducted at b-values up to 1 x 104 smm-2 yielded biexponential signal attenuation curves for both normal and ischemic brain. The relative fractions of the rapidly and slowly decaying components (f1, f2) are f1 = 0.80 ± 0.02, f2 = 0.17 ± 0.02 in healthy adult rat brain and f1 = 0.90 ± 0.02, f2 = 0.11 ± 0.01 in normal neonatal rat brain, whereas the corresponding values for the postmortem situation are f1 = 0.69 ± 0.02, f2 = 0.33 ± 0.02. It is demonstrated that the changes in f1 and f2 occur simultaneously to those in the extracellular and intracellular space fractions (f(ex), f(ln)) during: (i) cell swelling after total circulatory arrest, and (ii) the recovery from N-methyl-D- aspartate induced excitotoxic brain edema evoked by MK-801, as measured by changes in the electrical impedance. Possible reasons for the discrepancy between the estimated magnitude components and the physiological values are presented and evaluated. Implications of the biexponential signal attenuation curves for diffusion-weighted imaging experiments are discussed.
AB - Diffusion-weighted single voxel experiments conducted at b-values up to 1 x 104 smm-2 yielded biexponential signal attenuation curves for both normal and ischemic brain. The relative fractions of the rapidly and slowly decaying components (f1, f2) are f1 = 0.80 ± 0.02, f2 = 0.17 ± 0.02 in healthy adult rat brain and f1 = 0.90 ± 0.02, f2 = 0.11 ± 0.01 in normal neonatal rat brain, whereas the corresponding values for the postmortem situation are f1 = 0.69 ± 0.02, f2 = 0.33 ± 0.02. It is demonstrated that the changes in f1 and f2 occur simultaneously to those in the extracellular and intracellular space fractions (f(ex), f(ln)) during: (i) cell swelling after total circulatory arrest, and (ii) the recovery from N-methyl-D- aspartate induced excitotoxic brain edema evoked by MK-801, as measured by changes in the electrical impedance. Possible reasons for the discrepancy between the estimated magnitude components and the physiological values are presented and evaluated. Implications of the biexponential signal attenuation curves for diffusion-weighted imaging experiments are discussed.
KW - cytotoxic edema
KW - NMR spectroscopy
KW - rat brain
KW - water diffusion
UR - http://www.scopus.com/inward/record.url?scp=0029856791&partnerID=8YFLogxK
U2 - 10.1002/mrm.1910360607
DO - 10.1002/mrm.1910360607
M3 - Article
C2 - 8946350
AN - SCOPUS:0029856791
SN - 0740-3194
VL - 36
SP - 847
EP - 857
JO - Magnetic resonance in medicine
JF - Magnetic resonance in medicine
IS - 6
ER -