A syringe system for delivering fluid with a volume displacement assembly intensifier for expelling a predetermined volume of fluid from the syringe while activated. A syringe having a barrel and a syringe plunger is selectively operable to deliver fluid from the syringe barrel, and the volume displacement assembly is mounted in fluid communication with the barrel of the syringe. When the volume displacement assembly is activated, a predetermined amount of volume is displaced from the syringe into the balloon of a balloon catheter. Deactivation results in balloon deflation. A predetermined degree of inflation may be reproducibly obtained without the exercise of deliberate care as required with conventional syringes lacking a volume displacement assembly.