G01R33/4836

Methods and apparatus for scan time reductions in magnetic resonance imaging using outer volume supression

Methods for fast magnetic resonance imaging (MRI) using a combination of outer volume suppression (OVS) and accelerated imaging, which may include simultaneous multislice (SMS) imaging, data acquisitions amenable to compressed sensing reconstructions, or combinations thereof. The methods described here do not introduce fold-over artifacts that are otherwise common to reduced field-of-view (FOV) techniques.

Apparatus and method for spatial encoding using a radio frequency signal in magnetic resonance tomography

An apparatus and a method for spatial encoding in magnetic resonance tomography using a radio frequency signal are provided. A first set of parameters from a first frequency and from a first amplitude, and from a second frequency and a second amplitude is determined by the magnetic resonance tomograph, and corresponding signals are generated by a radio frequency device and transmitted by an antenna apparatus. A first gradient above the Larmor frequency of the nuclear spins is generated by the Bloch-Siegert effect. The same thing ensues with a second set of parameters that differs from the first set of parameters at least in one frequency or amplitude and therefore generates a second, different gradient.

Method and device for correcting a B0 inhomogeneity by a radio frequency signal

A method for correcting a B0 inhomogeneity in a magnetic resonance scan with a magnetic resonance tomograph is provided. The magnetic resonance tomograph includes a controller, a radio frequency unit, and a transmitting antenna. In the method, the controller determines a transmission signal that is suitable for correcting an effect of an inhomogeneity of a static B0 magnetic field in an examination volume by the Bloch-Siegert effect. The transmission signal is emitted into the examination volume.

Method and apparatus for generating magnetic resonance images
10768257 · 2020-09-08 · ·

In a method, control computer and magnetic resonance (MR) apparatus for generating MR recordings of an examination object, first magnetic MR data are acquired in a first recording region inside a homogeneity volume of the scanner of the MR apparatus, and second MR raw data are acquired in a second recording region outside the homogeneity volume. First image data are reconstructed on the basis of the first MR raw data and second image data are reconstructed on the basis of the second MR raw data. The first image data and the second image data are combined to form combination image data, which cover a region that extends in the first recording region and in the second recording region.

4D flow measurements of the hepatic vasculatures with two-dimensional excitation
10588523 · 2020-03-17 · ·

A computer-implemented method of visualizing blood flow through a patient using magnetic resonance imaging (MRI) includes receiving an image of the portal venous system of the patient's liver at a full field of view. A reduced field of view is defined which encompasses the portal venous system of the patient's liver and excludes extraneous anatomy in the full field of view. A navigator area is defined in the full field of view and outside of the reduced field of view. Transmit channels are used to selectively excite the reduced field of view and the navigator area throughout a cardiac cycle of the patient. Measurement data is acquired in response to the selective excitation. The acquired data is used to generate time-resolved 3D datasets. Additionally, a 3D visualization of blood flow though the portal venous system is generated based on the time-resolved 3D datasets.

MAGNETIC RESONANCE IMAGING APPARATUS AND MAGNETIC RESONANCE IMAGING METHOD
20200049781 · 2020-02-13 · ·

According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry sets an excitation pulse sequence that applies an excitation pulse including an inversion pulse between at least one set of sub pulses of a local excitation radio frequency pulse formed of a plurality of sub pulses, and applies a spoiler gradient magnetic field that disperses transverse magnetization while applying the inversion pulse. The processing circuitry controls execution of the excitation pulse sequence by applying the excitation pulse and the spoiler gradient magnetic field according to the excitation pulse sequence, and collects a magnetic resonance signal based on a data collecting sequence after execution of the excitation pulse sequence.

System and method for acquiring both T2*-weighted and T1-weighted data in a single acquisition using a single dose of contrast agent
10545209 · 2020-01-28 · ·

Described here are systems and methods for obtaining measurements of both tissue perfusion and permeability with a magnetic resonance imaging (MRI) system after the administration of a single dose of contrast agent. To this end, the MRI system is directed to acquire T2*-weighted data, during which the acquired signal values are monitored for a trigger event. When the trigger event occurs, the MRI system is directed to switch from acquiring the T2*-weighted data to acquiring T1-weighted data. The systems and methods of the present invention can thus be used for a fully automated, single acquisition of perfusion and permeability measurements using only a single dose of contrast agent.

METHOD AND APPARATUS FOR GENERATING MAGNETIC RESONANCE IMAGES
20190317168 · 2019-10-17 · ·

In a method, control computer and magnetic resonance (MR) apparatus for generating MR recordings of an examination object, first magnetic MR data are acquired in a first recording region inside a homogeneity volume of the scanner of the MR apparatus, and second MR raw data are acquired in a second recording region outside the homogeneity volume. First image data are reconstructed on the basis of the first MR raw data and second image data are reconstructed on the basis of the second MR raw data. The first image data and the second image data are combined to form combination image data, which cover a region that extends in the first recording region and in the second recording region.

Magnetic resonance imaging apparatus and magnetic resonance imaging method
10441182 · 2019-10-15 · ·

Provided is a technique in MRI to efficiently suppress downstream blood in a specific region in a blood vessel having a slow flow velocity, such as the portal vein. For this purpose, a plurality of Beam Sat pulses are applied so as to equally suppress signals of blood flowing into a desired imaging region from a desired blood vessel during the period from applying an IR pulse to starting main imaging. Downstream blood in a specific region in a blood vessel having a slow flow velocity, such as the portal vein, can be suppressed efficiently by determining application conditions of the plurality of Beam Sat pulses that achieve the above based on a flow velocity of blood in a desired blood vessel and T1 of the said blood.

APPARATUS AND METHOD FOR SPATIAL ENCODING USING A RADIO FREQUENCY SIGNAL IN MAGNETIC RESONANCE TOMOGRAPHY

An apparatus and a method for spatial encoding in magnetic resonance tomography using a radio frequency signal are provided. A first set of parameters from a first frequency and from a first amplitude, and from a second frequency and a second amplitude is determined by the magnetic resonance tomograph, and corresponding signals are generated by a radio frequency device and transmitted by an antenna apparatus. A first gradient above the Larmor frequency of the nuclear spins is generated by the Bloch-Siegert effect. The same thing ensues with a second set of parameters that differs from the first set of parameters at least in one frequency or amplitude and therefore generates a second, different gradient.