Provided is a method for delivering a medical fluid. The method includes delivering a fluid volume, which includes contrast and/or a flush fluid, at a preselected total volumetric flowrate during a first duration of a fluid delivery procedure. The amount of the contrast agent and the flush fluid in the fluid volume can be controllably varied during the first duration of the fluid delivery procedure so as to substantially maintain a preselected total volumetric flowrate throughout the first duration of the fluid delivery procedure. Also provided is a fluid delivery system capable of performing this method.