A syringe adapter assembly 10 for permitting a front loadable power injector 100 having a pressure jacket 106 with an open front end to attach syringes 70 that do not require pressure jackets for their intended purpose. The syringe adapter assembly comprises a main adapter body 12 having a central bore 28 therethrough, a lifting ring 60 secured within the main adapter body 12, a connector plate 50 for attaching the main adapter body to the door injector, and a drive ram extender 30 that attaches to the drive ram. Additionally, the ram extender 30 may have a ram tip cone 40 attached at its forward end. The connector plate 50 is inserted into a recess 112 in the rear side of the door, and attaches to the main adapter body 12 located on the front side of the door. The invention additionally or alternatively comprises both a syringe lock 120 that locks an installed syringe relative to the injector to prevent unwanted movement of the syringe, and a method of locking syringe relative to an injector.