DVR_ref_Logan {tacmagic}

Non-invasive reference Logan method

Description

This calculates the coefficient from the non-invasive Logan method, which is equal to DVR. Works for a single tac (target).

Usage

DVR_ref_Logan(
  tac_data,
  target,
  ref,
  k2prime,
  t_star,
  error = 0.1,
  method = "trapz"
)

Arguments

tac_data

The time-activity curve data from tac_roi()

target

The name of the target ROI, e.g. "frontal"

ref

The reference region, e.g. "cerebellum"

k2prime

A fixed value for k2' must be specified (e.g. 0.2)

t_star

If 0, t* will be calculated using find_t_star()

error

For find_t_star()

method

Method of integration, "trapz" or "integrate"

Value

Data frame with calculate DVRs for all ROIs

References

Logan, J., Fowler, J. S., Volkow, N. D., Wang, G.-J., Ding, Y.-S., & Alexoff, D. L. (1996). Distribution Volume Ratios without Blood Sampling from Graphical Analysis of PET Data. Journal of Cerebral Blood Flow & Metabolism, 16(5), 834-840. https://doi.org/10.1097/00004647-199609000-00008

See Also

Other Logan plot functions: DVR_all_ref_Logan(), dvr(), plot.ref_Logan()

Examples

f <- system.file("extdata", "AD06.tac", package="tacmagic")
fv <- system.file("extdata", "AD06_TAC.voistat", package="tacmagic")
AD06_tac <- load_tac(f, format="PMOD")
AD06_volume <- load_vol(fv, format="voistat")
AD06 <- tac_roi(tac=AD06_tac, volumes=AD06_volume, ROI_def=roi_ham_pib(),  
                merge=FALSE, PVC=FALSE)                             
               
AD06_DVR_fr <- DVR_ref_Logan(AD06, target="frontal", ref="cerebellum",
                             k2prime=0.2, t_star=0)