fit_ppf - tpcclib 0.7.3 © 2019 by Turku PET Centre

Fits an empirical function to plasma parent (unchanged) tracer
fraction curve (1), where the fractions are between 0 and 1.
 
Usage: fit_ppf [Options] fractionfile [fitfile]
 
Options:
 -model=<PF | HILL | MPF | MHILL>
     Select the function (see descriptions below); default is HILL.
     Use MPF or MHILL to fit functions to 2-3 metabolite fraction curves
     instead of parent fraction curve.
 -min=<OLS|LAD>
     Sum-of-squares (OLS) is minimized by default, but optionally
     sum of absolute deviations (LAD) can be selected.
 -delaymin=<value>
     Set the lower limit for delay parameter.
 -mdelay=<separated | joint>
     Delay parameter for each metabolite is fitted separately, or
     all metabolites are assumed to share common delay time (default).
 -a=<value>, -b=<value>, -c=<value>, ...
     Specified parameter is fixed to given (population mean) value.
 -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.
 -WP=<weight>, -WM1=<weight>, -WM2=<weight>, -WM3=<weight>
     Put additional or less weight to parent and/or metabolite fractions.
 -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 at least two columns: sample times (min) and
fractions of parent tracer. Fractions of 1-3 metabolites can be given in
additional columns. Weights column can be given as specified in
DFT format (2) or with option -wc.
Program writes the fit start and end times, nr of points, WSS,
and parameters of the fitted function to the FIT file (3).
 
Available functions:
PF - extended power function (1,4,5)
  f(x) = {D^(-1/C) + (A*(x-E))^B }^-C , when x>E,
  f(x) = D                            , when x<=E ,
  where 0<A<=1, B>1.5, C>0, 0<D<=1, 0<=E.
  With option -d=1 this is essentially the same function as proposed in (4)
  or with options -b=2 -d=1 -e=0 the same as suggested in (5).
HILL - Extended Hill type function (1,6)
  f(x) = D - {(D-A)(x-E)^B}/{C+(x-E)^B} , when x>E,
  f(x) = D                              , when x<=E ,
  where 0<=A<=D, 1<=B, 0<C, 0<D<=1, 0<=E.
  With options -d=1 -e=0 this is the traditional Hill type function (6)
  f(x) = 1 - {(1-A)x^B}/(C+x^B)
MPF - Extended power function is fitted to 1-3 metabolite fractions.
MHILL - Extended Hill type function is fitted to 1-3 metabolite fractions.
 
References:
1. Fitting the fractions of parent tracer in plasma.
   http://www.turkupetcentre.net/analysis/doc/fraction_fit.html
2. http://www.turkupetcentre.net/analysis/doc/format_dft.html
3. http://www.turkupetcentre.net/analysis/doc/format_fit.html
4. Meyer PT, Bier D, Holschbach MH, Boy C, Olsson RA, Coenen HH, Zilles K,
   Bauer A. Quantification of cerebral A1 adenosine receptors in humans
   using [18F]CPFPX and PET. J Cereb Blood Flow Metab. 2004;24(3):323-333.
5. Watabe H, Channing MA, Der MG, Adams HR, Jagoda E, Herscovitch P,
   Eckelman WC, Carson RE. Kinetic analysis of the 5-HT2A ligand
   ([11C]MDL 100,907. J Cereb Blood Flow Metab 2000;20:899-909.
6. Wu S, Ogden RT, Mann JJ, Parsey RV. Optimal metabolite curve fitting for
   kinetic modeling of 11C-WAY-100635. J Nucl Med 2007;48:926-931.
 
See also: fit2dat, metabcor, avgfract, fitedit, fit_fexp, fith2met, tac2svg
 
Keywords: input, plasma, modelling, simulation, metabolite correction