Calculate the influx rate constant Ki with this software. patlak can calculate the influx (uptake) rate constant Ki (ml/(min*ml)) as slope of the Gjedde-Patlak plot 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 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; 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.

The license of this software is Freeware, you can free download and free use this calculator software.