An injector for injecting a fluid from a syringe, which includes an elongated body, a mounting member positioned on a rear portion of the body, and a plunger moveably positioned within the body of the syringe, includes a housing having a front wall and a retainer on the front wall. The retainer is adapted to cooperate with the mounting member to releasably retain the syringe on the front wall. The retainer includes a powered loader adapted to bring the mounting member and the retainer into secure engagement to securely connect the syringe to the injector. The injector further includes a powered drive member in the housing. The drive member is adapted to engage the plunger and control the movement of the plunger.