A power injector (40), comprising a powerhead (50), first and second syringes (86a,86b) interconnected with said powerhead, first and second syringe plunger drivers (74) configured to interact with respective first and second syringe plungers (90a,90b) of said first and second syringes (respectively) so as to move said first and second plungers in advancing and retracting directions, a graphical user interface (52), and control logic that comprises a syringe plunger driver retraction protocol to retract said first and second plungers, wherein said control logic is configured to present first and second options on said graphical user interface, wherein said first option is to enable automatic initiation of said syringe plunger driver retraction protocol to retract said first and second plungers, and wherein said second option is to enable manual initiation of said syringe plunger driver retraction protocol via user input to retract said first and second plungers.
