fit_fexp - tpcclib 0.8.0 © 2023 by Turku PET Centre
Fits the following exponential function to plasma parent (unchanged) tracer
fraction curve, where fractions are between 0 and 1 (1,2).
-B*x -C*x
f(x) = 1 - A * (2 - e -e ) , where 0<A<=1 , B>0 , C>0
Optionally a monoexponential function, where fractions are between A and B,
can be applied instead:
-C*x
f(x) = (A-B) * e + B , where 0<A<=1 , B>=0 , C>0
Usage: fit_fexp [Options] fractionfile [fitfile]
Options:
-mono
Use monoexponential function.
-a=<value> or -a=zero
Parent fraction at time zero (A) is fixed to given value, or to
the value of zero sample, if available.
Applicable only with monoexponential function.
-WC
The last data column contains sample weights.
-W1
All weights are set to 1.0 (no weighting)
-WF
Less frequent samples are given more weight.
-ND
Some fractions are known to exceed 1, not divided by 100.
-MRL
Error is returned if MRL check is not passed.
-svg=<Filename>
Fitted and measured TACs are plotted in specified SVG file.
-h, --help
Display usage information on standard output and exit.
-v, --version
Display version and compile information on standard output and exit.
-d[n], --debug[=n], --verbose[=n]
Set the level (n) of debugging messages and listings.
-q, --quiet
Suppress displaying normal results on standard output.
-s, --silent
Suppress displaying anything except errors.
Fraction datafile must contain two columns, sample times (min) and fractions
of parent tracer. Weights can be specified as specified in DFT format (4);
any additional columns are ignored.
Lines that start with a '#' are not read from the datafile.
Program writes the fit start and end times, nr of points, WSS/n,
and parameters of the fitted function to the FIT file (5).
References:
1. Fitting the fractions of parent tracer in plasma.
http://www.turkupetcentre.net/petanalysis/input_parent_fitting.html
2. Kropholler MA, Boellaard R, Schuitemaker A, van Berckel BNM, Luurtsema G,
Windhorst AD, Lammertsma AA. Development of a tracer kinetic plasma input
model for (R)-[11C]PK11195 brain studies. J Cereb Blood Flow Metab. 2005;
25(7): 842-851.
4. http://www.turkupetcentre.net/petanalysis/format_tpc_dft.html
5. http://www.turkupetcentre.net/petanalysis/format_tpc_fit.html
See also: fit2dat, metabcor, avgfract, fit_ppf, fit_dexp, tac2svg
Keywords: input, plasma, modelling, simulation, metabolite correction