TY - JOUR
T1 - Water proton MR properties of human blood at 1.5 Tesla
T2 - Magnetic susceptibility, T1, T2*, T2, and non-Lorentzian signal behavior
AU - Spees, William M.
AU - Yablonskiy, Dmitriy A.
AU - Oswood, Mark C.
AU - Ackerman, Joseph J.H.
PY - 2001
Y1 - 2001
N2 - Accurate knowledge of the magnetic properties of human blood is required for the precise modeling of functional and vascular flow-related MRI. Herein are reported determinations of the relaxation parameters of blood, employing in vitro samples that are well representative of human blood in situ. The envelope of the blood 1H2O free-induction decay signal magnitude during the first 100 msec following a spin echo at time TE is well-described empirically by an expression of the form, S(t) = So · exp{-R2* · (t - TE) - AR* · (t - TE)2}. The relaxation parameters AR* and R2* increase as a function of the square of the susceptibility difference between red blood cell and plasma and depend on the spin-echo time. The Gaussian component, AR*, should be recognized in accurate modeling of MRI phenomena that depend upon the magnetic state of blood. The magnetic susceptibility difference between fully deoxygenated and fully oxygenated red blood cells at 37°C is 0.27 ppm, as determined independently by MR and superconducting quantum interference device (SQUID) measurements. This value agrees well with the 1936 report of Pauling and Coryell (Proc Natl Acad Sci USA 1936;22:210-216), but is substantially larger than that frequently used in MRI literature.
AB - Accurate knowledge of the magnetic properties of human blood is required for the precise modeling of functional and vascular flow-related MRI. Herein are reported determinations of the relaxation parameters of blood, employing in vitro samples that are well representative of human blood in situ. The envelope of the blood 1H2O free-induction decay signal magnitude during the first 100 msec following a spin echo at time TE is well-described empirically by an expression of the form, S(t) = So · exp{-R2* · (t - TE) - AR* · (t - TE)2}. The relaxation parameters AR* and R2* increase as a function of the square of the susceptibility difference between red blood cell and plasma and depend on the spin-echo time. The Gaussian component, AR*, should be recognized in accurate modeling of MRI phenomena that depend upon the magnetic state of blood. The magnetic susceptibility difference between fully deoxygenated and fully oxygenated red blood cells at 37°C is 0.27 ppm, as determined independently by MR and superconducting quantum interference device (SQUID) measurements. This value agrees well with the 1936 report of Pauling and Coryell (Proc Natl Acad Sci USA 1936;22:210-216), but is substantially larger than that frequently used in MRI literature.
KW - BOLD effect
KW - Blood
KW - Functional MRI
KW - Magnetic susceptibility
KW - Relaxation
UR - http://www.scopus.com/inward/record.url?scp=0035095912&partnerID=8YFLogxK
U2 - 10.1002/mrm.1072
DO - 10.1002/mrm.1072
M3 - Article
C2 - 11283978
AN - SCOPUS:0035095912
SN - 0740-3194
VL - 45
SP - 533
EP - 542
JO - Magnetic resonance in medicine
JF - Magnetic resonance in medicine
IS - 4
ER -