According to preferred embodiments and methods of the present disclosure, a medical injection system employs a single pump for the injection of multiple fluids, rather than employing a pump for each type of fluid, for example, like the prior art system described above. Embodiments of pumps disclosed herein preferably include a disposable pump cartridge configured to be contained within a hull of a medical injection system, wherein the hull may be formed when a pressure plate member is closed against a base plate and, when the pressure plate member is opened with respect to the base plate, the disposable pump cartridge may be removed and replaced.
