G01R33/5676

METHOD FOR PERFORMING A MAGNETIC RESONANCE MEASUREMENT OF A PATIENT, MAGNETIC RESONANCE APPARATUS, AND COMPUTER PROGRAM PRODUCT
20220296119 · 2022-09-22 ·

A method for performing a magnetic resonance measurement of a patient using a magnetic resonance apparatus is provided. The magnetic resonance apparatus includes a radiofrequency antenna unit for producing an excitation pulse. A first B0 field map for a first motion state of the patient, and a second B0 field map for a second motion state of the patient are provided. A first excitation pulse for the first motion state, and a second excitation pulse for the second motion state are determined based on the first B0 field map and the second B0 field map. A magnetic resonance measurement is performed, during which the motion state of the patient is monitored. When the patient is in the first motion state, the radiofrequency antenna unit transmits the first excitation pulse. When the patient is in the second motion state, the radiofrequency antenna unit transmits the second excitation pulse.

MAGNETIC RESONANCE VOLUMETRIC IMAGING

Reference data relating to a portion of a patient anatomy during patient motion can be acquired from a magnetic resonance imaging system (MRI) to develop a patient motion library. During a time of interest, tracking data is acquired that can be related to the reference data. Partial volumetric data is acquired during the time of interest and at approximately the same time as the acquisition of the tracking data. A volumetric image of patient anatomy that represents a particular motion state can be constructed from the acquired partial volumetric data and acquired tracking data.

MRI system comprising patient motion sensor

A table for an MRI system includes a top surface for supporting a patient being imaged and a motion sensor for sensing motion of the patient. The motion sensor is located below the top surface and includes a self-resonant spiral (SRS) coil and a coupling loop. The coupling loop generates a drive RF signal to excite the SRS coil to radiate a magnetic field having a predefined resonant frequency. The coupling loop also receives a reflection RF signal from the SRS coil. The motion sensor is located such that at least a portion of a torso of the patient being imaged is within the magnetic field. A controller is configured to detect patient motion based on the reflection RF signal.

Magnetic resonance volumetric imaging

Reference data relating to a portion of a patient anatomy during patient motion can be acquired from a magnetic resonance imaging system (MRI) to develop a patient motion library. During a time of interest, tracking data is acquired that can be related to the reference data. Partial volumetric data is acquired during the time of interest and at approximately the same time as the acquisition of the tracking data. A volumetric image of patient anatomy that represents a particular motion state can be constructed from the acquired partial volumetric data and acquired tracking data.

Magnetic resonance Dixon method
11275138 · 2022-03-15 · ·

Techniques are disclosed for acquiring at least two measurement datasets, each consisting of measurement data. The two measurement datasets are recorded at points in time at which spins of a first spin species present in the examination object have different phase positions from spins of a second spin species present in the examination object. Moreover, the two measurement datasets are recorded in each case while switching readout gradients of different polarity, and thus the desired measurement datasets may be recorded faster than conventional approaches.

Preventing interruptions in magnetic resonance measurements
11300641 · 2022-04-12 · ·

A system and method for performing a measuring sequence by a magnetic resonance device for examining a patient is provided. The performance of the measuring sequence includes a processing of segments. If at least one determined patient load value exceeds a predetermined limit value, the processing of the measuring sequence for the time frame of exceeding the patient load value is interrupted. The determination of the at least one patient load value includes a detection of a movement of a patient into a changed pose, an adjustment of at least one following segment to the changed pose of the patient, and a determination of at least one patient load value for the adjusted at least one following segment.

System and method for performing motion-insensitive and quiet three-dimensional magnetic resonance imaging

A method for generating motion-corrected medical images includes obtaining, via a processor, k-space data of a region of interest acquired by a magnetic resonance imaging system utilizing a 3D radial pulse sequence with ZTE acquisition including optional magnetization preparation pulses. The method also includes sampling, via the processor, the k-space data to obtain a plurality of interleaved k-space segments. The method further includes reconstructing, via the processor, one or more interleaved k-space segments of the plurality of interleaved k-space segments to generate a respective motion navigator volume. The method even further includes co-registering, via the processor, each respective motion navigator volume to estimate motion and performing motion correction on the one or more interleaved k-space segments and their corresponding k-space trajectories. The method still further includes generating, via the processor, a motion-corrected volume from all of the motion corrected interleaved k-space segments and their corresponding motion corrected k-space trajectories.

Magnetic resonance imaging apparatus
11294017 · 2022-04-05 · ·

A navigator echo is acquired during imaging, and when frequency is corrected based on phase change, the correction is performed with high accuracy without being affected by an offset caused by variations with time. An MRI apparatus including a navigation controller is configured to control an imaging unit acquiring an NMR signal, generate the navigator echo and collect navigation data during a predetermined measurement time, prior to collection of nuclear magnetic resonance signals for reconstructing an image of a subject. The phase change of the navigator echo is analyzed during the measurement time to calculate a correction value for correcting misalignment due to the phase change with a navigation analyzer that calculates a phase change amount relative to a reference, based on a difference between the phase change of the navigator echo and the phase change of the navigator echo serving as the reference during the measurement time.

System and method for motion correction of magnetic resonance image

A method for motion correction of Magnetic Resonance (MR) images is provided. The method includes acquiring a k-space dataset for an object using an MR scanner, detecting or identifying corrupted k-space data from the acquired k-space dataset, extracting the corrupted k-space data from the acquired k-space dataset, recovering the corrupted k-space data, combining uncorrupted k-space data of the acquired k-space dataset with the recovered k-space data to form a full k-space dataset, and reconstructing an image for the object based on the full k-space dataset. A magnetic resonance imaging system for correcting corrupted k-space data of an entire k-space dataset is also provided.

MR imaging using motion-dependent radial or spiral k-space sampling

The invention relates to a method of MR imaging of an object (10) placed in an examination volume of a MR device (1). It is an object of the invention to enable MR imaging using a radial (or spiral) acquisition scheme with a reduced level of motion artefacts. The method of the invention comprises the following sequence of steps: —detecting a momentary motion—induced displacement (Δ) of the object (10); —attributing the detected displacement (A) to a motion state (M1-M5), each motion state (M1-M5) corresponding to one of a plurality of contiguous ranges of displacements (Δ); —determining angular coordinates of a radial or spiral k-space profile by incrementing the angular coordinates individually for each motion state (M1-M5) starting from initial angular coordinates; —acquiring the k-space profile; —repeating steps a-d a number of times; and —reconstructing an MR image from at least the k-space profiles attributed to one of the motion states (M1-M5). Moreover, the invention relates to a MR device (1) for carrying out this method as well as to a computer program to be run on a MR device (1).