A magnetic resonance imaging (MRI) system with low-power miniaturization, a power supply system, and a power management system are provided. The MRI system includes: a permanent magnet using samarium-cobalt material, an MR console, a transmission RF chain, a receiving RF chain, gradient coils, gradient amplifiers, and a terminal device for user interactions. Each of above systems is a ultra-light and ultra-low-power ultra-low field brain MRI system for highly accessible healthcare applications.

Gradient power amplifier (GPA) systems and methods are provided. A GPA system may include a plurality of paralleled GPAs; and at least one controller operably coupled to the plurality of paralleled GPAs. The at least one controller may be configured to perform operations including: obtaining a total current parameter of the plurality of paralleled GPAs; determining, based on the total current parameter and a target current parameter, a first difference value; and determining, based on the first difference value, a first control parameter of a first GPA of the plurality of paralleled GPAs, wherein the first control parameter is configured to control an output current of the first GPA.

The present disclosure relates to an MRI system and a method and device for determining a waveform of oblique scanning. Specifically, provided are a magnetic resonance imaging system, a method and device for determining a gradient waveform of oblique scanning, and a computer-readable storage medium. The method includes: generating an initial physical axis gradient waveform on a physical axis, the physical axis including a first physical axis, a second physical axis, and a third physical axis, wherein gradient waveforms on the three physical axes have the same inflection time; converting the initial physical axis gradient waveform into a logical axis gradient waveform, an inflection point of the logical axis gradient waveform being the same as the inflection time of the initial physical axis gradient waveform; re-converting the logical axis gradient waveform into a physical axis gradient waveform; and using, during the oblique scanning of magnetic resonance imaging, the converted physical axis gradient waveform to drive a gradient amplifier.

A method for operating an MR system with a gradient power amplifier having at least one output stage that is connectable to a gradient coil, and having four switching elements connected to one another as an H-bridge includes, to operate the gradient coil, in alternation: switching the switching elements attached to a common first pole of a voltage supply to conductive and switching the switching elements attached to a common second pole of a voltage supply to blocking by inverting power drivers; and switching the switching elements attached to a common first pole of a voltage supply to blocking and switching the switching elements attached to a common second pole of a voltage supply to conductive by inverting power drivers. The switching elements attached to the first pole are switched by non-inverting power drivers, and the switching elements attached to the second pole are switched by inverting power drivers.

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.

The disclosure relates to a gradient system comprising a first gradient coil unit, a second gradient coil unit and a flexible gradient amplifier unit, wherein the flexible gradient amplifier unit is configured to actuate the first gradient coil unit and the second gradient coil unit.

The present disclosure directs to a system and method for configuring a pulse sequence in MRI. The method may include obtaining a preliminary gradient pulse configuration, wherein the preliminary gradient pulse configuration relates to a portion of a pulse sequence to be implemented by one or more coils of an MR scanner, the pulse sequence including a plurality of gradient pulses. The method may also include determining a global peripheral nerve stimulation (PNS) value of the preliminary gradient pulse configuration according to a PNS model. The method may further include determining a target gradient pulse configuration based at least in part on the preliminary gradient pulse configuration, the global PNS value, and a PNS threshold.

Improvements in MR spiral imaging are provided in that spiral segments (2 to 8) are reordered, in particular alternately traversed and/or permuted. Moreover, repeatedly approaching the same post-trajectory points (16) between the acquisitions of the spiral segments (2 to 8) is provided, in which the post-trajectory points (16) are located outside of the center (18) of k-space (9), preferably outside of a region (20) of the k-space (9) covered by the spiral segments (2 to 8).

Described herein are power components that may facilitate efficient, low noise operation of low-field MRI systems. In some embodiments, the power components may include switching power converters configured to switch in a manner that reduces or eliminates noise within a desired frequency band (e.g., the Larmor frequency band) due to harmonics of the switching frequency. For example, the desired frequency band may be positioned between adjacent integer harmonics of the switching frequency. In some embodiments, harmonic components generated by multiple switching power converters may destructively interfere with one another, reducing or eliminating the amplitude of the harmonic components of the switching frequency that reside in the desired frequency band. In some embodiments, the power components may include switching power converters configured in parallel without the need for active current balancing circuitry.

The present disclosure provides a system for MRI. The system may obtain MRI scan data of a subject by directing an MRI scanner to perform an MRI scan on the subject according to a first gradient waveform. The system may also determine a second gradient waveform based on the first gradient waveform and a gradient waveform determination model. The gradient waveform determination model may have been trained according to a machine learning algorithm. The system may further generate a target reconstruction image of the subject based on the second gradient waveform and the MRI scan data.