The present disclosure relates to systems and methods for shielding electromagnetic waves. The system may include an imaging device, a shielding layer assembly disposed on at least a first portion of the imaging device, and a shielding cover assembly disposed on at least a second portion of the imaging device. When the shielding cover assembly is coupled to the shielding layer assembly, the shielding cover assembly and the shielding layer assembly may be combined to form a shielding space that is shielded against electromagnetic waves from an outside of the shielding space.

Electromagnetic interference (“EMI”) is mitigated for portable magnetic resonance imaging (“MRI”) systems using postprocessing interference suppression techniques that make use of EMI detectors external to the MRI system imaging volume to detect EMI signals and remove them from acquired magnetic resonance data. EMI correction models, including static transfer function-based models, dynamic transfer function-based models, correction weight-based models, or parallel imaging kernel-based models can be used to remove the EMI-related artifacts from the magnetic resonance data.

Electromagnetic interference (“EMI”) is mitigated for portable magnetic resonance imaging (“MRI”) systems using postprocessing interference suppression techniques that make use of EMI detectors external to the MRI system imaging volume to detect EMI signals and remove them from acquired magnetic resonance data. EMI correction models, including static transfer function-based models, dynamic transfer function-based models, correction weight-based models, or parallel imaging kernel-based models can be used to remove the EMI-related artifacts from the magnetic resonance data.

A cable for operating a gradient coil of a magnetic resonance apparatus, a magnetic resonance apparatus, and a method for manufacturing a cable for operating a gradient coil of a magnetic resonance apparatus are provided. The cable includes at least one electric conductor and a stabilizing sheathing that surrounds the at least one electric conductor at least partially.

A curtain for shielding an electromagnetic field may include a plurality of strip elements. A first strip element and a second strip element of the plurality of strip elements may have an electrically conductive layer. In a shielding configuration of the curtain, the electrically conductive layer of the first strip element is electrically connected to the electrically conductive layer of the second strip element and/or to an electrical connecting terminal for a reference potential. The plurality of strip elements can be variably positioned against one another.

A method and apparatus for limiting an RF alternating magnetic field in MRI. The method includes: measuring a perpendicular distance between a local coil placed on a scanned part of a patient and the center of a detection hole of a magnetic resonance (MR) scanner; based on the perpendicular distance, determining a deviation between the B1 field strength at the position of the local coil during an MR scan and the B1 field strength at the center of the detection hole; based on the deviation, computing a conversion coefficient for conversion between the B1 field strength at the position of the local coil and the B1 field strength at the center of the detection hole; based on the B1 field strength required when the surface temperature of the local coil is equal to a safe temperature upper limit and the conversion coefficient, computing a maximum permissible field strength of the B1 field at the center of the detection hole. The B1 field may be limited to a smaller but still effective field strength range, reducing wastage of B1 field performance while ensuring patient safety and MR imaging quality

A method and apparatus for limiting an RF alternating magnetic field in MRI. The method includes: measuring a perpendicular distance between a local coil placed on a scanned part of a patient and the center of a detection hole of a magnetic resonance (MR) scanner; based on the perpendicular distance, determining a deviation between the B1 field strength at the position of the local coil during an MR scan and the B1 field strength at the center of the detection hole; based on the deviation, computing a conversion coefficient for conversion between the B1 field strength at the position of the local coil and the B1 field strength at the center of the detection hole; based on the B1 field strength required when the surface temperature of the local coil is equal to a safe temperature upper limit and the conversion coefficient, computing a maximum permissible field strength of the B1 field at the center of the detection hole. The B1 field may be limited to a smaller but still effective field strength range, reducing wastage of B1 field performance while ensuring patient safety and MR imaging quality

A whole-body coil for a magnetic resonance tomography device includes one or more compensation capacitors between a high-frequency antenna and an RF shield. The one or more compensation capacitors each have variable capacitance caused by a variation in a distance of the RF shield to the high-frequency antenna.

An MR-PET apparatus is provided. The MR-PET apparatus may include a supporting component, a PET detection device, an RF coil, and a signal shielding component. The PET detection device may be supported on the supporting component. The PET detection device may be configured to receive a plurality of photons. The RF coil may be configured to generate or receive a radio frequency (RF) signal. The signal shielding component may be placed between the PET detection device and the RF coil. The signal shielding component may be configured to shield the PET detection device from at least part of the RF signal.

In some aspects, a magnetic system for use in a low-field MRI system. The magnetic system comprises at least one electromagnet configured to, when operated, generate a magnetic field to contribute to a B.sub.0 field for the low-field MRI system, and at least one permanent magnet to produce a magnetic field to contribute to the B.sub.0 field.