fitk5 - tpcclib 0.8.0 © 2023 by Turku PET Centre

Non-linear fitting of irreversible three-tissue compartment model to plasma
input, blood, and tissue time-activity curves (PTAC, BTAC, and TTAC) to
estimate parameters K1, K1/k2, k3, k3/k4, k5, and Vb.
 
Model with two of tissue compartments in parallel:
  _____         ____         ____  
 |     |   K1  |    |   k3  |    | 
 |  Ca | ----> |    | ----> | C2 | 
 |_____|       |    | <---- |____| 
  _____        | C1 |   k4   ____  
 |     |       |    |       |    | 
 |  Cv | <---- |    | ----> | C3 | 
 |_____|   k2  |____|   k5  |____| 
 
Model with compartments in series:
  _____         ____         ____         ____  
 |     |   K1  |    |   k3  |    |  k5   |    | 
 |  Ca | ----> |    | ----> | C2 | ----> | C3 | 
 |_____|       |    | <---- |____|       |____| 
  _____        | C1 |   k4                      
 |     |       |    | 
 |  Cv | <---- |    | 
 |_____|   k2  |____| 
 
Sample times must be in minutes.
 
Usage: fitk5 [Options] ptacfile 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 file name the default values are printed on screen.
 -SD[=<y|N>]
     Standard deviations are estimated and saved in results (y),
     or not calculated (N, default).
     Program runs a lot faster if SD and CL are not calculated.
 -CL[=<y|N>]
     95% Confidence limits are estimated and saved in results (y), or
     not calculated (N, default).
 -model=<parallel|series>
     Specify the model that is fitted to data; compartments in parallel
     (default) or in series.
 -Vb=<Vb(%)>
     Enter a fixed Vb; fitted by default.
 -fk1k2=<<value> || <result filename>>
     K1/k2 is constrained to the given value in all regions; if result
     file name is entered, then K1/k2 is constrained to the median of
     regional K1/k2 values in the result file.
 -fit=<Filename>
     Fitted regional TACs are written in DFT format.
 -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.
 
Example 1: estimate K1, K1/k2, k3, k3/k4, k5 and Vb
     fitk5 -svg=ua929fit.svg ua929ap.bld ua929ab.bld ua929.tac 90 ua929.res
 
Example 2: estimate K1, k3, k3/k4, and k5; Vb is constrained to 1.5%, and
K1/k2 is constrained to the regional median
     fitk5 -Vb=1.5 ua929ap.kbq ua929ab.kbq ua929.tac 90 tmp.res
     fitk5 -Vb=1.5 -fk1k2=tmp.res ua929ap.kbq ua929ab.kbq ua929.tac 90 ua929.res
 
See also: logan, fitk2, fitk3, fitk4, p2t_v3c, tacweigh, rescoll
 
Keywords: TAC, modelling, Ki, k5, irreversible uptake, 3TCM