A solution is proposed for operating an injection system comprising a pressurizing unit and at least one supply station for supplying a medical fluid to the pressurizing unit, the supply station comprising at least one receptacle for containing said medical fluid, a delivery arrangement in fluid communication with the receptacle and the pressurizing unit for delivering the medical fluid to a patient, and clamping means associated with the delivery arrangement for regulating the flow of the medical fluid through the delivery arrangement. The method comprises the steps of: operating the pressurizing unit till a first injection procedure is completed； maintaining the injection system in a standby condition before a second injection procedure is started, and operating the pressurizing unit till the second injection procedure is completed. The step of maintaining the injection system in a standby condition comprises the step of acting on the clamping means for de-clamping the delivery arrangement.
