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