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 |
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
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.
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.
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.
95% Confidence limits are calculated and saved in results (y), or
not calculated (N, default).
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.
Fitted regional TACs are written in DFT format.
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.
Weighted residual curves are written in DFT format.
Fitted and measured TACs are plotted in specified SVG file.
Save k2 in result file.
Display usage information on standard output and exit.
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.
Suppress displaying normal results on standard output.
Suppress displaying anything except errors.
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