Mr compatible rotating anode x-ray tube

An x-ray tube for use in a magnetic resonance (MR) system, which generates an external MR magnetic field, comprising:

• an anode;
• a motor for rotating the anode;
• a cathode is spaced apart from the anode;
• an external magnetic field sensor that measures the external MR magnetic field;
• a plurality of active shielding magnets spaced surrounding a path from the cathode to the anode;
• a controller connected to the external magnetic field sensor and the plurality of active shielding magnets.

An x-ray tube for use in a magnetic resonance (MR) system, which generates an external MR magnetic field, comprising:

• an anode;
• a motor for rotating the anode, comprising:
• a rotor, comprising:
• a rotor shaft with an axis along a length of the rotor shaft;
• and
• a plurality of coils on the rotor shaft;
• a housing supporting and surrounding the rotor, wherein a part of the housing surrounds sides of the rotor, wherein the part of the housing surrounding sides of the rotor is magnet free;
• a mount for mounting the housing to the MR system in a location where the MR system provides a magnetic field, wherein a component of the MR magnetic field that is perpendicular to the axis of the rotor shaft is at least 100 Gauss;
• an active timer for applying a voltage to the plurality of coils with alternating polarity;
• and
• contacts for providing an electrical connection between the active timer and the plurality of coils;
• and
• a cathode spaced apart from the anode.