Abstract: A plastic syringe adapted for use with power injector systems comprises a cylindrical barrel for receiving a liquid, a plunger axially reciprocable within the barrel for discharging the liquid therefrom, a discharge extension at the distal end of the barrel terminating in a discharge outlet, at least one radially outwardly extending mounting lug located at or near the outer proximal end of the barrel, the lug having a distal surface having first and second ends defining a constrained portion of the barrel, and the lug being crown shaped such that the center of the distal surface of the lug is distally offset from the ends of the lug. In another embodiment, the syringe comprises a cylindrical collar adapted to fit over and attach to the proximal end of the cylindrical barrel, and the crowned lug is located at or near the outer proximal end of the collar.