Kinetic Models for Arterial Spin Labeling

Theoretical models for the acquisition of pulsed ASL data.

See Buxton etal. (1998) for more details.

asl2p(beta, TI, T1b = 1.3, T1 = 1, tau = 1, alpha = 0.9, lambda = 0.9,
  Mob = 4095)

asl3p(beta, TI, T1b = 1.3, T1 = 1, alpha = 0.9, lambda = 0.9,
  Mob = 100)

Arguments

beta	is a vector (lenth = 2 or 3) of kinetic parameters.
TI	is a vector of inversion times (TIs) in seconds.
T1b	is the longitudinal relaxation time of blood.
T1	is the longitudinal relaxation time of tissue.
tau	is the first TI in the second paper (?).
alpha	is the fraction of maximum possible change in the longitudinal magnetization that was achieved.
lambda	is the equilibrium tissue/blood partition coefficient of water.
Mob	is the equilibrium magnetization of arterial blood.

Value

A theoretical curve of pulsed ASL signal as a function of time.

Author

Brandon Whitcher bjw34032@users.sourceforge.net

References

Buxton, R.B., Frank, L.R., Wong, E.C., Siewert, B., Warach, S. and Edelman, R.R. (1998) A General Kinetic Model for Quantitative Perfusion Imaging with Arterial Spin Labeling, Magnetic Resonance in Medicine, 40, 383-396.

Examples

TI <- seq(0, 3, length=256)
beta <- c(f=0.8, deltaT=0.5)
plot(TI, asl2p(beta, TI), type="l", lwd=2,
     xlab="Time (sec)", ylab="Signal", main="Pulsed ASL: Standard Model")
abline(v=1.5, lwd=2, col=2)