A method for using a syringe in an injector system, the method comprising: providing a syringe that includes a pumping chamber and a plunger inserting an actuator into the plunger and deforming the plunger to preclude further use by removing the actuator from the plunger. Preferably, the plunger comprises a plurality of tabs that extend inward towards a centre of the plunger, which are broken when the actuator is removed from the plunger.