calib4ge 2.3  © 1997-2003 by Turku PET Centre
  Calibrates GE Advance images in CTI ECAT 6.3 format to kBq/mL.
  Corrects also for isotope branching ratio.
  Note that this program does not remove previous calibration, but just
  adds to those, and thus file must not be initially calibrated!
  Usage:  calib4ge [-f<Frame(s)>] [-d] <Image> <Calibration file>
  With option -f the calibration can be applied only to specified 'frames';
  this can be used with images reconstructed from parametric sinograms.
  Independent of this option, all frames are divided by the volume of pixel.
  With option -d calibration is made directly from calibration factors.