A fluid injection apparatus comprises at least one pressurizing mechanism, at least a first fluid container operably associated with the at least one pressurizing mechanism, and a controller operably associated with the at least one pressurizing mechanism. The at least first fluid container is adapted to contain a first fluid to be injected. The controller comprises a programming system to allow programming of an injection protocol comprising at least one phase. The fluid injection apparatus further comprises a system adapted to determine if a pressure to be generated during the at least one phase exceeds a pressure threshhold based upon at least one of the parameters of the phase.
