blmod_feng_startpars: Create starting parameters for an Feng blood model

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

Create starting parameters for an Feng blood model

Description

This function estimates reasonable starting parameters for the Feng blood models. I use the suggestions from Tonietto (2012).

Usage

blmod_feng_startpars(time, activity, expdecay_props = c(0, 0.5))

Arguments

time	The time of each measurement.
activity	The radioactivity of each measurement.
expdecay_props	What proportions of the decay should be used for choosing starting parameters for the exponential decay. Defaults to 0 and 0.5, i.e. the latter two exponentials, B, C, beta, gamma are estimated using halfway to the end of the decay, and the beginning to halfway through the decay. The first parameters, A and alpha, are estimated from the ascent.

Value

A list of the starting parameters

Author(s)

Granville J Matheson, [e-mail]

References

Tonietto, M. (2012). Methods and models for the characterization of arterial input function in dynamic PET studies. Master thesis.

Examples

blooddata <- pbr28$blooddata[[1]]
blooddata <- bd_blood_dispcor(blooddata)
aif <- bd_extract(blooddata, output = "AIF")
start <- blmod_feng_startpars(aif$time,
                           aif$aif)

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