Method and apparatus for shielding a linear accelerator and a magnetic resonance imaging device from each other

A radiation therapy system, comprising:

• a magnetic resonance imaging (MRI) system, the MRI system including first and second main MRI magnets configured for generating a magnetic field,
• wherein the first and second main MRI magnets are separated by an MRI magnet gap, and extend radially about a first longitudinal axis;
• a gantry positioned in the MRI magnet gap, the gantry being rotatable about the first longitudinal axis;
• a linear particle accelerator (linac) supported by the gantry at a fixed radial distance from the first longitudinal axis, the linac being configured to rotate with the gantry and configured to direct a radiation beam along a second longitudinal axis towards the first longitudinal axis;
• and
• a magnetic shield supported by the gantry at a second fixed radial distance from the first longitudinal axis,
• wherein the magnetic shield includes at least a first shell and a second shell, the first shell extending coaxially with the linac and at least partially both the linac and the second shell, and
• wherein at least one of the first shell and the second shell is formed of a material that includes steel.

A radiation therapy system, comprising:

• a magnetic resonance imaging (MRI) system, the MRI system including first and second main MRI magnets configured for generating a magnetic field,
• wherein the first and second main MRI magnets are separated by an MRI magnet gap, and extend radially about a first longitudinal axis;
• a linear particle accelerator (linac) positioned in the MRI magnet gap at a fixed radial distance from the first longitudinal axis, the linac being configured to rotate about the first longitudinal axis and configured to direct a radiation beam along a second longitudinal axis towards the first longitudinal axis;
• and
• a first magnetic shield supported by a gantry at a second fixed radial distance from the first longitudinal axis,
• wherein the first magnetic shield includes at least a first shell and a second shell, the first shell extending coaxially with the second longitudinal axis and at least partially surrounding both the linac and the second shell, and
• wherein at least one of the first shell and the second shell is formed of a material that includes steel.

A radiation therapy system, comprising:

• a magnetic resonance imaging (MRI) system, the MRI system including first and second main MRI magnets separated by an MRI magnet gap, the first and second main MRI magnets being configured to produce a magnetic field along at least a portion of a longitudinal axis of the MRI system;
• a gantry positioned in the MRI magnet gap, the gantry being rotatable about the longitudinal axis;
• a linear particle accelerator (linac) supported by the gantry at a fixed radial distance from the longitudinal axis of the MRI system, the linac being configured to rotate with the gantry and configured to direct a radiation beam towards the longitudinal axis of the MRI system, the linac being configured to produce RF radiation;
• and
• a shield supported by the gantry, the shield including at least a first shell and a second shell, the first shell at least partially surrounding both the linac and the second shell,
• wherein at least one of the first shell is formed of a first material that includes steel or the second shell is formed of a second material that includes steel.

A radiation therapy system, comprising:

• a magnetic resonance imaging (MRI) system, the MRI system including first and second main MRI magnets separated by an MRI magnet gap, the first and second main MRI magnets being configured to produce a magnetic field along at least a portion of a longitudinal axis of the MRI system;
• a linear particle accelerator (linac) supported at a fixed radial distance from the longitudinal axis of the MRI system, the linac being configured to direct a radiation beam towards the longitudinal axis of the MRI system, the linac being configured to produce RF radiation;
• and
• an RF shield including at least a first shell and a second shell, the first shell at least partially surrounding both the linac and the second shell,
• wherein at least one of the first shell is formed of a first material that includes steel or the second shell is formed of a second material that includes steel.