The invention relates to an adapter for a syringe plunger. The adapter of some embodiments may include a first side adapted to interface with a syringe plunger and an opposing a second side adapted to interface with a drive ram of a medical fluid injector. The adapter may include a peripheral side surface exhibiting a thickness and may include what may be characterized as at least one mating section adapted to engage with the syringe plunger. The mating section(s) may include a channel extending through the entire thickness of the adapter. In some embodiments, the mating section(s) may include a stop adjacent the channel that extends less than the entirety of the thickness of the adapter.