An auto purge for an intravenous contrast injector (20) of the type having amotor which advances a plunger drive ram and configured for use with a pre-filled or user-filled syringe containing an approximate known amount of airincluding a processor which causes the motor to move and a memory storing apredetermined purge stop point representative of the approximate known amountof air in the syringe, the injector configured to automatically advance theplunger drive ram an amount substantially equal to the predetermined purgestop point representative of the approximate known amount of air contained inthe syringe.
