Functionality is available in the separate module which is activated in the Pro edition for an extra fee
To open the settings dialog select main menu Options->Settings...-> Modules->PET analysis and click the Settings button. You can set up the following parameters in the dialog that opens:
The Common tab:
In the Controllers MIP you can associate tools with mouse wheel and move operations for the MIP window, in the Controllers 2D you can do it for the CT and PET windows.
The settings are applied the next time you open the PET Analysis window.
To change the PET layer opacity in the CT+PET window move the slider at the top of the CT+PET window (marked with number "1" in Fig. 9.2).