metab_gamma: Fit the Gamma Function for Modelling Parent Fraction.

In mathesong/kinfitr: Kinetic Modelling of PET Time Activity Curves

Fit the Gamma Function for Modelling Parent Fraction.

Description

This function fits the integrated gamma function to parent fraction data.

Usage

metab_gamma(
  time,
  parentFraction,
  fit_ppf0 = FALSE,
  fit_delay = FALSE,
  lower = list(a = 0.8, b = 0.3, c = 0, d = 0, delay = -30),
  upper = list(a = 1.1, b = 3, c = 20, d = 1e+06, delay = 30),
  multstart_lower = NULL,
  multstart_upper = NULL,
  multstart_iter = 1000
)

Arguments

time	Time in seconds.
parentFraction	Measured values of parent fraction.
fit_ppf0	Should the starting plasma parent fraction be fitted? Otherwise, it is set to 1. Defaults to FALSE.
fit_delay	Should the delay of the plasma parent fraction be fitted? Otherwise, it is set to 0. Defaults to FALSE.
lower	Named list of the lower limits.
upper	Named list of the upper limits.
multstart_lower	Named list of the lower starting limits.
multstart_upper	Named list of the upper starting limits.
multstart_iter	Number of fits to perform before deciding on an optimal.

Value

An nls fit object.

References

Naganawa M, Jacobsen LK, Zheng MQ, Lin SF, Banerjee A, Byon W, Weinzimmer D, Tomasi G, Nabulsi N, Grimwood S, Badura LL. Evaluation of the agonist PET radioligand [11C] GR103545 to image kappa opioid receptor in humans: Kinetic model selection, test–retest reproducibility and receptor occupancy by the antagonist PF-04455242. Neuroimage. 2014 Oct 1;99:69-79.

Examples

## Not run: 
pf <- bd_getdata(blooddata, output = "parentFraction")
metab_gamma(pf$time, pf$parentFraction)

## End(Not run)

mathesong/kinfitr documentation built on Jan. 15, 2024, 11:07 p.m.