fit_h2o - tpcclib 0.8.0 © 2023 by Turku PET Centre

Non-linear fitting of one-tissue compartmental water model to regional
dynamic PET [O-15]H2O study data.
The model parameters are blood flow (F), partition coefficient
(pWater, K1/k2), arterial blood volume (Va) and time delay (delayT) between
tissue and blood time-activity curves (TTAC and BTAC, respectively).
Venous radioactivity is assumed to be the same as the tissue concentration.
Extraction factor of water is assumed to be 1.0.
 
    ______        ______    
   |      |  K1  |      |   
   |  Ca  | ---> |  C1  |   
   |______|      |______|   
                    | k2    
                    V       
 
The blood flow obtained using PET [O-15]H2O techniques reflects tissue
perfusion, since the method is dependent on the tissue exchange of
labelled water. Non-nutritive flow (blood flowing through arteriovenous
shunts) is not measured (Lammertsma & Jones, 1983).
 
Usage: fit_h2o [Options] btacfile ttacfile endtime resultfile
 
Options:
 -lim[=<filename>]
     Specify the constraints for model parameters;
     This file with default values can be created by giving this
     option as the only command-line argument to this program.
     Without filename the default values are printed on screen.
     Parameter can be fixed to a certain value by setting its
     lower and upper limit to that value.
 -ml or -dl
     In results the units of F and Va will be given per mL or per dL,
     respectively. By default, units are per dL.
 -fpt
     Blood flow (perfusion) is reported per tissue volume (PET volume minus
     vascular volume), that is, F=K1. By default, perfusion is reported
     per PET volume, that is, F=(1-Va)*K1.
 -SD[=<y|N>]
     Standard deviations are calculated and saved in results (Y, default),
     or not calculated (n).
     Program runs a lot faster if SD and CL are not calculated.
 -CL[=<y|N>]
     95% Confidence limits are calculated and saved in results (y), or
     not calculated (N, default).
 -Va=<Va(%)>
     Enter a fixed Va; fitted by default.
 -Delay=<Time delay (s)>
     Enter a fixed time delay; fitted by default.
     Positive time delay means that BTAC is moved forward in time.
 -pH2O=<Partition coefficient for water>
     Enter a fixed pH2O; fitted by default.
 -fit=<Filename>
     Fitted regional TACs are written in DFT format.
 -input=<Filename>
     Input TAC sample times are corrected by the median of fitted time
     delay values and saved; resulting input file can be used with imgflow,
     or as input to this program to have common time delay for all regions.
 -resid=<Filename>
     Weighted residual curves are written in DFT format.
 -svg=<Filename>
     Fitted and measured TACs are plotted in specified SVG file.
 -k2
     Save k2 in result 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.
 
Example:
     fit_h2o uo1234bl.kbq uo1234.dft 999 uo1234f.res
 
See also: b2t_h2o, imgflow, arlkup, water_input, fitk2, bfmh2o
 
Keywords: TAC, modelling, perfusion, blood flow, 1TCM