Abstract: A system and method for reducing MRI-generated acoustic noise is disclosed. A system control of an MRI apparatus causes a plurality of gradient coils and an RF coil assembly in the MRI apparatus to generate pulse sequences that each cause an echo train to form and acquire blades of k-space data of the subject of interest from the pulse sequences, with the blades being rotated about a section of k-space compared to every other blade. The system control also causes the plurality of gradient coils to generate gradient pulses in each pulse sequence having an optimized gradient waveform that reduces an acoustic noise level generated thereby and causes the RF coil assembly to generate a 180 degree prep pulse subsequent to generation of an RF excitation pulse and prior to generation of a first RF refocusing pulse, the 180 degree prep pulse minimizing echo spacing in the echo train.

Abstract: A system and method for reducing MRI-generated acoustic noise is disclosed. A system control of an MRI apparatus causes a plurality of gradient coils and an RF coil assembly in the MRI apparatus to generate pulse sequences that each cause an echo train to form and acquire blades of k-space data of the subject of interest from the pulse sequences, with the blades being rotated about a section of k-space compared to every other blade. The system control also causes the plurality of gradient coils to generate gradient pulses in each pulse sequence having an optimized gradient waveform that reduces an acoustic noise level generated thereby and causes the RF coil assembly to generate a 180 degree prep pulse subsequent to generation of an RF excitation pulse and prior to generation of a first RF refocusing pulse, the 180 degree prep pulse minimizing echo spacing in the echo train.

Abstract: A system and method for reducing MRI-generated acoustic noise is disclosed. A system control of an MRI apparatus causes a plurality of gradient coils and an RF coil assembly in the MRI apparatus to generate pulse sequences that each cause an echo train to form and acquire blades of k-space data of the subject of interest from the pulse sequences, with the blades being rotated about a section of k-space compared to every other blade. The system control also causes the plurality of gradient coils to generate gradient pulses in each pulse sequence having an optimized gradient waveform that reduces an acoustic noise level generated thereby and causes the RF coil assembly to generate a 180 degree prep pulse subsequent to generation of an RF excitation pulse and prior to generation of a first RF refocusing pulse, the 180 degree prep pulse minimizing echo spacing in the echo train.

Abstract: A system and method for reducing MRI-generated acoustic noise is disclosed. A system control of an MRI apparatus causes a plurality of gradient coils and an RF coil assembly in the MRI apparatus to generate pulse sequences that each cause an echo train to form and acquire blades of k-space data of the subject of interest from the pulse sequences, with the blades being rotated about a section of k-space compared to every other blade. The system control also causes the plurality of gradient coils to generate gradient pulses in each pulse sequence having an optimized gradient waveform that reduces an acoustic noise level generated thereby and causes the RF coil assembly to generate a 180 degree prep pulse subsequent to generation of an RF excitation pulse and prior to generation of a first RF refocusing pulse, the 180 degree prep pulse minimizing echo spacing in the echo train.

Abstract: A platform configured to be mounted onto a body support. The platform includes a body portion having an underside and an opposite top side. The underside is configured to face the body support, and the top side is configured to support a patient. The body portion also has a coil-receiving recess along the underside. The coil-receiving recess is configured to form a coil-receiving gap when the platform is mounted onto the body support. The coil-receiving gap is sized and shaped to permit a radio-frequency (RF) coil to be positioned therein.

Abstract: A gamma ray detector ring for a combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system is integrated into a radio frequency (RF) coil assembly such that the detector ring is integrated with a RF shield. Each gamma ray detector in the detector ring includes a scintillator component that emits light when a gamma ray is detected and a photodetector component designed to be sensitive to the frequency of light produced by the scintillator. A RF shield may be integrated into a detector ring such that the RF shield is positioned between the scintillator and photodetector components of each detector, thereby saving valuable radial space within the imaging system. Multiple such detector rings may be located adjacent to one another to increase axial coverage and enable three-dimensional PET imaging techniques.

Abstract: A method for compensating for drift in a main magnetic field of a superconducting magnet in a magnetic resonance imaging (MRI) system includes measuring a pressure in a cryostat of the superconducting magnet. Based on the pressure, a parameter of an element of the MRI system is adjusted to correct or compensate for a change in the main magnetic field.

Abstract: A gamma ray detector ring for a combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system is integrated into a radio frequency (RF) coil assembly such that the detector ring is integrated with a RF shield. Each gamma ray detector in the detector ring includes a scintillator component that emits light when a gamma ray is detected and a photodetector component designed to be sensitive to the frequency of light produced by the scintillator. A RF shield may be integrated into a detector ring such that the RF shield is positioned between the scintillator and photodetector components of each detector, thereby saving valuable radial space within the imaging system. Multiple such detector rings may be located adjacent to one another to increase axial coverage and enable three-dimensional PET imaging techniques.

Abstract: A magnetic resonance imaging device has a compensation circuit for compensating for magnetic disturbances therein. The compensation circuit includes a sensor for sensing magnetic field changes and generating a magnetic field change signal. The sensor is coupled to a control circuit that has a transfer function therein. The control circuit is used to generate a compensation signal in response to the magnetic field change signal. The compensation signal may be coupled to the compensation coils located by the first magnet portion and the second magnet portion of the device. Also, the compensation signal may produce a time-dependent bias or change the center frequency to cancel magnetic disturbances.

Abstract: The present invention, in one form, provides compensation for the effects of an oscillatory B0 eddy current Be(t) in an NMR apparatus. In an NMR apparatus having a transmitter generating a spin excitation signal and a receiver detecting an NMR signal, applied gradient signals are analyzed to estimate a resulting oscillatory B0 eddy current Be(t). The frequency of either the transmitter or the receiver of the NMR apparatus, or both, is shifted in frequency by an amount proportional to Be(t) to achieve compensation.

Abstract: An MRI system produces magnetic field gradients along physical axes during a patient scan. The gradients are specified as logical gradient waveforms in a pulse sequence and these are stored in a logical vector table. A physical vector table is produced by rotating amplitude values in the logical vector table, and the resulting rotated amplitude values are used to calculate the heating in each gradient axis of the MRI system.

Abstract: A calibration procedure for correcting geometric errors in MRI images due to gradient field non-linearities and magnetic field inhomogeneities includes performing a 3D scan on a calibration phantom. The calibration phantom contains an array of tapered rods that produce an array of spots in reconstructed slice images. Spot sizes and positions enable position errors to be measured throughout the bore of the imaging system. Corrective coefficients are produced from these 3D error measurements that enable subsequent patient images to be corrected for warping errors in object position.