The use of gas as a contrast medium has significant potential to avoid limitations of conventional contrast agents. Gases can transit smaller vascular conduits and can be injected through smaller and less traumatic access systems than liquids. Highly soluble gases (such as CO2) can be imaged as a bolus. Blood is displaced by the gas, with the result of negative image contrast.
Because gases are compressible, standard liquid injectors cannot be used. The design for a gasinjector should have the option for individual adaptation of blood flow rate, vessel diameter, pulse pressure, and heart rate.