Analyze TAC files with this utility. dftlevel help you with the calculation of sample mean over time frames in regional or blood time-activity curves (TACs).
Mean is not weighted by frame duration or sampling intervals; for that purpose use dftinteg with option -avg.

Parameters:
1) TAC file (*.dft)
2) Mean calculation start time
3) Mean calculation end time
4) Mean result file (*.dft or *.res)

Options:
-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.