An adapter for releasably attaching a syringe to an injector. The adapter comprises a mounting mechanism positioned at a rear end of the adapter to mount the adapter in a desired position relative to a front wall of the injector; and a syringe carrier section adapted to seat at least a portion of the syringe. The syringe carrier section defines a first opening on a top thereof to allow placement of the syringe therein from the top and a second opening in a rear section thereof to allow the drive member of the injector to communicate forward force to the plunger. A cover portion extends over a rearward end of the first opening and has a first end configured to abut the flange of the syringe when the syringe is positioned within the syringe carrier section.