A syringe for injecting contrast injection media into a patient. An inlet valve system associated with the syringe, the inlet valve system operable with a contrast injection media having any viscosity within the range of about 1 cP to about 30 cP. An inlet valve system associated with the syringe, the inlet valve system including a valve member having a density of less than or equal to 1 gram per cubic centimeter. A contrast injector system with such a syringe.