Analyze PET plasma curves with this tool. extrapol extrapolate exponentially decreasing tail of PET plasma curves. This is accomplished by fitting line to the end-part of the plot of the natural logarithm of tracer concentration against time. This approach may be applied to TACs which approach zero; thus this cannot be used with tracers like radiowater.
Plasmafile must contain a time column, and one or more concentration columns separated by space(s) or tabulator(s). File can also be in DFT format. The last extrapolation time must be given in same units as are the sample times in datafile.

Usage: extrapol [Options] <Plasmafile> <Last extrapolated time> <Output file>

Options:
-e[nd]=<Fit end time>
Start the search to fit end time; by default, the search for the best line fit is started from the last sample.
-minnr=<Minimum nr of samples>
Set the minimum number of samples used in searching the best fit; by default 3.
-maxnr=<Maximum nr of samples>
Set the maximum number of samples used in searching the best fit; by default all.
-mintime=<Minimum time>
Set a minimum time range used in searching the best fit.
-svg=<Filename>
Measured and extrapolated TACs are plotted in specified SVG file.
-h or --help
Print this message and exit.
--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.

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