An air ventilation device for use in a magnetic resonance imaging system, the air ventilation device comprising: —an electric motor-driven fan (30), —a fan housing (34) having at least one air intake opening (36) and at least one air outlet opening (38), wherein the fan (30) is arranged inside the fan housing (34) between the at least one air intake opening (36) and the at least one air outlet opening (38), —at least one ventilation duct (40) connected to the at least one air outlet opening (38), wherein the fan housing (34) is designed as an open-ended waveguide (24) for conveying electromagnetic waves having a cutoff frequency (fc) that is larger than a largest frequency of the emission spectrum that exceeds a predefined amplitude-related parameter, and wherein one end of the waveguide (24) serves as the at least one air intake opening (36), and the opposite end of the waveguide (24) serves as the at least one air outlet opening (38)； and a magnetic resonance imaging system comprising a scanner unit (10) that is configured for acquiring magnetic resonance images from a subject of some interest, and an embodiment of such air ventilation device.
