The invention provides for a magnetic resonance imaging (MRI) (100) system comprising a main magnet (102) with an with an adjustable main magnetic field. The MRI system further comprises a current source (124) for supplying RF current between multiple electrodes (122, 122) divided between a first portion (122) and a second portion (122). The current source is configured for supplying the RF current between the first portion and the second portion. Execution of the machine executable instructions cause a processor controlling the MRI system to: set (200) the average magnetic field strength within the imaging zone to a first value; set (202) the average magnetic field strength within the imaging zone to a second value, the second value is lower than the first value; control (204) the current source to have a known RF current (144) travel between the first portion of the electrodes and the second portion of the electrodes; acquire (206) the magnetic resonance data from the subject by controlling the magnetic resonance imaging system with readout gradient commands according to a three-dimensional imaging protocol; reconstruct (208) three-dimensional image data (148) from the magnetic resonance data; and calculate (210) a resistive model (150) of the subject using the three-dimensional image data and the known RF current through the electrodes.

The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142) from a subject (118) within an imaging zone (108). The magnetic resonance imaging system comprises a memory (134, 136) for storing machine executable instructions (160), and pulse sequence commands (140, 400, 502, 600, 700), wherein the pulse sequence commands are configured to cause the magnetic imaging resonance system to acquire the magnetic resonance data according to a magnetic resonance fingerprinting technique. The pulse sequence commands are further configured to control the magnetic resonance imaging system to perform spatial encoding using a zero echo time magnetic resonance imaging protocol. Execution of the machine executable instructions causes the processor controlling the MRI system to: acquire (200) the magnetic resonance data by controlling the magnetic resonance imaging system with the pulse sequence commands; and calculate (202) a spatial distribution (146) of each of a set of predetermined substances by comparing the magnetic resonance data with a magnetic resonance fingerprinting dictionary (144).

A system for magnetic resonance imaging a subject is provided. The system includes a magnet assembly and a controller. The controller is in electronic communication with the magnet assembly and operative to: perform an inversion recovery pulse on the subject via the magnet assembly; acquire an ultrashort echo from the subject via the magnet assembly using a hybrid encoding scheme; and generate an image of the subject based at least in part on the ultrashort echo.

Automated setting techniques for MR imaging with ultra-short echo times in a region to be examined are described. With the method protocol parameter values for an MR imaging method are determined. The protocol parameters comprise a predetermined imaging resolution. Optimized values for echo time and bandwidth are also determined based on an image signal simulation, which is based on the determined protocol parameters. The signal to noise ratio and point spread function are used as optimization criteria.

A system for bone imaging is disclosed. A processing unit is provided for processing an echo MRI dataset. The processing unit is configured to apply a phase ramp to the radial sampling lines of the complex data according to the radial sampling scheme to obtain a bone-enhanced image dataset, wherein a single phase ramp is applied to a radial sampling line of the sampling scheme, which radial sampling line extends on both sides of an origin defined by the echo time, and wherein the phase ramp is based on an equation. A combining unit is provided for combining the MRI dataset with the bone-enhanced image dataset to obtain a background suppressed image dataset.

A low-field magnetic resonance imaging (MRI) system. The system includes a plurality of magnetics components comprising at least one first magnetics component configured to produce a low-field main magnetic field B.sub.0 and at least one second magnetics component configured to acquire magnetic resonance data when operated, and at least one controller configured to operate one or more of the plurality of magnetics components in accordance with at least one low-field zero echo time (LF-ZTE) pulse sequence.

An object positioned in an examination volume of a magnetic resonance (MR) device (1) is T2-weighted MR imaged such that the MR image is essentially free from interfering contributions from MR signals without T2 weighting. The object (10) is subject to a first T2 preparation sequence (T2PREP1) including an excitation RF pulse (21), one or more refocusing RF pulses (22), and a tip-up RF pulse (23). The object (10) is subject to a first readout sequence (RO1) including at least one excitation RF pulse and switched magnetic field gradients for acquiring a first set of MR signals. The object (10) is subject to a second T2 preparation sequence (T2PREP2) including an excitation RF pulse (21), one or more refocusing RF pulses (22), and a tip-up RF pulse (23). At least one of the RF pulses (21, 22, 23) of the second T2 preparation sequence (T2PREP2) has a different phase than the corresponding RF pulse (21, 22, 23) of the first T2 preparation sequence (T2PREP1). The object (10) is subject to a second readout sequence (RO2) including at least one excitation RF pulse and switched magnetic field gradients for acquiring a second set of MR signals. The MR image is reconstructed from the first and second sets of MR signals.

Some aspects of the present disclosure relate to ultrashort-echo-time (UTE) imaging. In one embodiment, a method includes acquiring UTE imaging data associated with an area of interest of a subject. The acquiring comprises applying an imaging pulse sequence with a three-dimensional (3D) spiral acquisition and a nonselective excitation pulse. The method also includes reconstructing at least one image of the area of interest from the acquired UTE imaging data.

Described here are systems and methods for magnetic resonance imaging (MRI) using a sweeping frequency excitation applied during a time-varying magnetic field gradient. As an example, a gradient-modulated offset independent adiabaticity (GOIA) approach can be used to modify the pattern of the sweeping frequency excitation. Data are acquired as time domain signals and processed to generate images. As an example, the time domain signals are processed using a correlation between a Fourier transform of the gradient-modulated sweeping frequency excitation and a Fourier transform of the time domain signals.

Systems and methods for producing pseudo-CT images using a dual flip angle multi-echo ultra-short echo time (DUFA-MUTE) MRI method are disclosed. The DUFA-MUTE MRI imaging method includes obtaining MR signals according to a DUFA-MUTE MRI sequence that includes first and second multiple ultrashort echo time (MUTE) sequence characterized by first and second flip angles FA1/FA2, and in which both MUTE sequences obtain MR signals at first and second echo times TE1/TE2. HU values are assigned to each imaged voxel based on each voxel's R1 value calculated from the MR signals, as well as each voxel's assigned tissue type. The imaged voxels and assigned HU values are combined to produce a pseudo-CT image. Pseudo-CT images optionally form the basis for attenuation maps suitable for use in combined PET/MRI systems and/or electron density maps suitable for use in radiation therapy systems.