A power-injectable access port suitable for injecting contrast media therethrough at a rate of at least 1 milliliter per second. The access port includes a housing, a septum, a reservoir, and an outlet stem in fluid communication with the reservoir. The power-injectable access port is structured for accommodating a pressure developed within the reservoir of at least 35 psi. The septum may include a radiopaque material forming a selected pattern when an x-ray is taken through the septum. The pattern may identify the access port as capable of accommodating injection of contrast media at a rate of at least 1 milliliter per second and/or as capable of accommodating a pressure developed within the reservoir of at least 35 psi. The pattern may identify the location of the septum following implantation of the power-injectable access port.