patlak 1.8.6 © 2001-2012 by Turku PET Centre
Calculates the influx (uptake) rate constant Ki (ml/(min*ml)) as slope of
the Gjedde-Patlak plot (1,2,3) from regional PET time-activity curves (TACs).
Parameters:
1) Tissue TAC file
2) Name of plasma file OR reference region name in TAC file
3-4) Start and end times for linear fit (min)
5) Result file (existing file is overwritten)
Options for calculation of metabolic rate:
-Ca=<value>
Concentration of native substrate in arterial plasma (mM),
for example plasma glucose in [18F]FDG studies.
With this option the metabolic rate (umol/(min*100 g)) is calculated.
-LC=<value>
Lumped Constant in MR calculation; default is 1.0.
-density=<value>
-d=<value>
Tissue density in MR calculation; default is 1.0 g/ml.
General options:
-ic=<y axis intercept>
Force y axis intercept to specified value; for FUR or Ri calculation
use regfur.
-sd=<y|n>
Standard deviations are saved (y, default) or not saved (n) in results.
-mid=<Y|n>
Frame middle times are used (y), or not used (n, default), even if frame
start and end times are available. For compatibility with old software.
-svg=<Filename>
Plots are written in specified file in Scalable Vector Graphics (SVG) 1.1
format; specification in
http://www.w3.org/TR/SVG/
-plotdata=<Filename>
Data for plots is written in specified file in XHTML 1.1 table format
for easy importing in Excel or OpenOffice spreadsheet, where the data
can be viewed;
http://www.turkupetcentre.net/analysis/doc/plotting.html#plotting_mtga
If filename extension is .dft, data is written in DFT format.
-h or --help
Print this message and exit.
-v, --version or --build
Print software build information and exit.
--silent
Program works silently, printing only error and warning messages.
--verbose
Program prints more information about what it is doing.
Options for selecting the least-squares line fit method:
-C Traditional regression model (default)
-M Median of two-point slopes and intercepts (Cornish-Bowden)
-P Perpendicular regression model (4)
-R Iterative method (York 1966, Lybanon 1984, Reed 1992)
In the present software version, the weights are not used in the fit.
Format of the tissue and input data files are specified in
http://www.turkupetcentre.net/analysis/doc/format_dft.html
Example 1: tissue curves are in ut1234.dat and plasma curve in ut1234ap.dat;
fitted data range is from 10 to 60 min; standard deviations are not needed:
patlak -nosd ut1234.dat ut1234ap.dat 10 60 ut1234.res
Example 2: tissue curves in ut1234.dft, including reference region 'cer';
plot is saved for viewing in ut1234pplot.svg:
patlak -svg=ut1234pplot.svg ut1234.dft cer 10 60 ut1234.res
References:
1. Gjedde A. Calculation of cerebral glucose phosphorylation from brain
uptake of glucose analogs in vivo: a re-examination. Brain Res. 1982;
257:237-274.
2. Patlak CS, Blasberg RG, Fenstermacher JD. Graphical evaluation of
blood-to-brain transfer constants from multiple-time uptake data.
J Cereb Blood Flow Metab 1983;3:1-7.
3. Patlak CS, Blasberg RG. Graphical evaluation of blood-to-brain transfer
constants from multiple-time uptake data. Generalizations.
J Cereb Blood Flow Metab 1985;5:584-590.
4. Varga J & Szabo Z. Modified regression model for the Logan plot.
J Cereb Blood Flow Metab 2002; 22:240-244.
See also:
imgki,
fitk3,
lhsolki,
regfur,
logan,
rescoll,
dfttime
Keywords: DFT, modelling, irreversible uptake, net influx rate, Ki
This program comes with ABSOLUTELY NO WARRANTY. This is free software, and
you are welcome to redistribute it under GNU General Public License.
