aslModels: Kinetic Models for Arterial Spin Labeling
In oro.asl: Rigorous - Aterial Spin Labelling

Description Usage Arguments Details Value Author(s) References Examples

Theoretical models for the acquisition of pulsed ASL data.

asl2p(beta, TI, T1b = 1.3, T1 = 1.0, tau = 0.7, alpha = 0.9,
      lambda = 0.9, Mob = 4095)
asl3p(beta, TI, T1b = 1.3, T1 = 1.0, alpha = 0.9, lambda = 0.9,
      Mob = 100)

`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.

See Buxton etal. (1998) for more details.

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

Brandon Whitcher bjw34032@users.sourceforge.net

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.

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)