An open-type MRI apparatus includes a pair of static magnetic field magnets and a pair of gradient magnetic field coils. Each static magnetic field magnet includes a discoid magnetic pole configured to generate a static magnetic field in a Z axis direction in which the pair of static magnetic field magnets are opposed each other, and an annular magnetic pole configured to generate a static magnetic field on an X-Y plane perpendicular to the Z axis direction. Each gradient magnetic field coil includes a Z coil configured to provide a magnetic field being gradient in the Z axis direction in the imaging region, a magnetic material block configured to shield the discoid magnetic pole from a magnetic flux generated from the Z coil, and a correction coil configured to shield the annular magnetic pole from the magnetic flux generated from the Z coil.

Shimming a magnetic field includes measuring the magnetic field and sampling it in a plurality of locations; defining a grid for positioning correction elements; calculating the position and magnitude parameters of one or more correction elements to obtain predetermined target values of the field characteristics, wherein an algorithm has been trained by a database of known cases in which each record links a certain initial magnetic field of a magnetic structure to the pattern of correction elements on a positioning grid for these correction elements in the magnet structure, thereby delivering as an output a pattern of correction elements on the positioning grid, which contributions to the magnetic field of the magnet structure generate a magnetic field which at least best approximates or meets the predetermined target values of the field characteristics.

Improved magnetic resonance imaging systems, methods and software are described including a low field strength main magnet, a gradient coil assembly, an RF coil system, and a control system configured for the acquisition and processing of magnetic resonance imaging data from a patient while utilizing a sparse sampling imaging technique.

The disclosure describes a magnet system for a magnetic resonance imaging system comprising a basic field magnet and a gradient system, wherein coils of the gradient system are positioned outside the area of a predefined basic magnetic field (B0) of the basic field magnet. The disclosure further describes a gradient system and a magnetic resonance imaging system with such a magnet system.

An electron paramagnetic resonance (EPR) apparatus has a main magnet with two pole pieces on either side of an air gap, and at least one EPR probe head adapted for rapid scan (RS) measurements positioned between the pole pieces of a main magnet, and a pair of RS coils. The EPR apparatus further has at least one EPR probe head adapted for continuous wave (CW) signal measurements, positioned between the pole pieces of the main magnet, and a carrier which allows insertion of the RS coils into the air gap between the pole pieces in an operation position and extraction of the RS coils from the air gap to a storage position outside of a CW operating volume. The system allows a quick and secure change of the RS coils, safely and rapidly, by a single user.

Systems and methods for the delivery of linear accelerator radiotherapy in conjunction with magnetic resonance imaging in which components of a linear accelerator may be placed in shielding containers around a gantry, may be connected with RF waveguides, and may employ various systems and methods for magnetic and radio frequency shielding.

An ion chamber has a chamber having an interior volume. There is a first electrode and a second electrode in the chamber and separated by a gap. A collector electrode is positioned between the first electrode and the second electrode. The collector electrode is shaped to occlude a portion of the first electrode from the second electrode.

According to some aspects, a laminate panel is provided. The laminate panel comprises at least one laminate layer including at least one non-conductive layer and at least one conductive layer patterned to form at least a portion of a B.sub.0 coil configured to contribute to a B.sub.0 field suitable for use in low-field magnetic resonance imaging (MRI).

According to some aspects, a method of suppressing noise in an environment of a magnetic resonance imaging system is provided. The method comprising estimating a transfer function based on multiple calibration measurements obtained from the environment by at least one primary coil and at least one auxiliary sensor, respectively, estimating noise present in a magnetic resonance signal received by the at least one primary coil based at least in part on the transfer function, and suppressing noise in the magnetic resonance signal using the noise estimate.

A hybrid imaging apparatus for imaging an object to be examined located in a sample volume can be operated in an MPI mode and in at least one further imaging mode and comprises a magnet arrangement embodied to generate, in the MPI mode, a magnetic field with a gradient B1 and a field-free region in the sample volume, wherein the magnet arrangement comprises a ring magnet pair with two ring magnets in a Halbach dipole configuration, which are arranged coaxially on a common Z-axis that extends through the sample volume, wherein the ring magnets are arranged so as to be twistable relative to one another about the Z-axis. Consequently, it is possible to generate magnetic fields that meet the requirements of both MRI and MPI such that the hybrid imaging apparatus can be equipped for measurements in various imaging modes, including MPI, MRI and CT.