Patent classifications
G01R33/5612
B1+ MAPPING NEAR METALLIC HARDWARE
A method can include obtaining a scaling factor for a location proximate a metallic object by optimizing a function of an acquired dataset and a simulated dataset. The simulated dataset can include a first signal from a first pulse having a first excitation flip angle and a first refocusing flip angle. The simulated dataset can include a second signal from a second pulse having a second excitation flip angle and a second refocusing flip angle.
SYSTEM AND METHOD FOR MAGNETIC RESONANCE IMAGING USING SHAPED RADIO FREQUENCY PULSES
A system and method are described for MRI excitation pulse design. The system can include a magnetic system that produces a main magnetic field over a portion of a subject for MRI imaging. The system can also include an RF system configured to transmit and receive an RF or B.sub.1.sup.+ field across at least a target region within the subject. The system may further include a gradient system configured to spatially encode the B.sub.1.sup.+ field using a gradient waveform. The system may also include a control system, which can be configured to control the RF system in order to generate an RF excitation pulse. The excitation pulse includes freely-shaped RF waveforms, gradient waveforms and, potentially shim array waveforms, selected by penalizing deviation of a flip-angle from a target distribution in order to achieve a target magnetization profile. The method can be applied to 3D and 2D slice-selective excitation and refocusing.
SYSTEMS AND METHODS OF NOISE REDUCTION IN MAGNETIC RESONANCE IMAGES
A computer-implemented method of reducing noise in magnetic resonance (MR) images is provided. The method includes executing a neural network model of analyzing MR images, wherein the neural network model is trained with a pair of pristine images and corrupted images. The pristine images are the corrupted images with noise reduced, and target output images of the neural network model are the pristine images. The method also includes receiving first MR signals and second MR signals, reconstructing first and second MR images based on the first MR signals and the second MR signals, and analyzing the first MR image and the second MR image using the neural network model. The method further includes deriving a denoised MR image based on the analysis, wherein the denoised MR image is a combined image based on the first MR image and the second MR image and outputting the denoised MR image.
Calibration of a magnetic resonance device and estimating a specific absorption rate
A method is provided for calibration of a magnetic resonance device with a transmitting device for generating an excitation field. In a first acquisition phase, a first transmitting coil element is detuned, at least one second transmitting coil element is tuned, and an MR data set is acquired using the transmitting device. In a second acquisition phase, the first transmitting coil element, the at least one second transmitting coil element are tuned, and at least one further MR data set is acquired using the transmitting device. By an arithmetic unit, a calibration factor is determined based on the MR data set and the at least one further MR data set for calculating a total voltage value at a feeding point of the first transmitting coil element from voltage values, which may be measured at a measuring point of an electrical supply line of the first transmitting coil element.
METHOD AND DEVICE FOR CONTROLLING A MAGNETIC RESONANCE IMAGING SYSTEM
A pulse-design unit for creating pulse data for controlling a magnetic resonance system includes a data interface configured for receiving an examination scheme, and a calculation module configured for generating pulse data based on an examination scheme. The pulse-design unit includes a data grid and/or parameter values created from map pairs of a plurality of patients and is configured to select and/or calculate pulse data using the data grid and/or parameter values and a provided examination scheme. A method and a control device for controlling a magnetic resonance imaging (MRI) system and a related magnetic resonance imaging system are also provided.
Multi-channel integrated MRI transmitter system for a magnetic resonance imaging device
A multi-channel RF transmitter system including a magnetic resonance imaging device, a multi-channel RF coil array, a control computer receiving required parameters from a user, producing triggering and clock signals and synthesizing input data required for each channel of RF coil array according to imaging scenario to be realized, an interface control module producing basic band MRI signals according to data from the control computer, a signal modulator and control module for modulating MRI signals produced at the interface control module into radio frequency and distribution to channels, a power/data distribution module distributing the produced signals and required DC power, a RF power amplifier module converting digital signal coming from the power/data distribution module into analog signal, amplifying it and transmitting to members of the coil array, a feedback line for track and correction of any errors in RF signal transmitted to the coil array by the power amplifier module.
Image acquisition method and apparatus using parallel scheme of radio frequency irradiation and data acquisition
Disclosed is an image acquisition method and apparatus using a parallel scheme of radio frequency irradiation and data acquisition. The image acquisition method includes saturating a labile proton by radiating a first radio frequency (RF) pulse signal to an object, generating a proton signal by radiating a pulse sequence signal to the object, and obtaining a chemical exchange saturation transfer (CEST) image of the object, and the generating and the obtaining of which are repeatedly performed in parallel.
BIOLOGICAL INFORMATION MONITORING APPARATUS AND MAGNETIC RESONANCE APPARATUS
In one embodiment, a biological information monitoring apparatus includes: an antenna assembly including at least one antenna, the antenna assembly being disposed close to an object; a signal generator configured to generate a high-frequency signal; and a displacement detection circuit configured to detect a physical displacement of the object based on the high-frequency signal, wherein the at least one antenna includes: a main antenna to be supplied with the high frequency signal; and a parasitic element to which the high frequency signal is not supplied.
METHOD OF DESIGNING A PULSE SEQUENCE FOR PARALLEL-TRANSMISSION MRI, AND A METHOD OF PERFORMING PARALLEL-TRANSMISSION MRI USING SUCH A PULSE SEQUENCE
A method of designing a pulse sequence for parallel-transmission MRI includes a) for each one of a plurality of subjects, estimating a linear adjustment transformation (L), converting amplitude maps of RF fields generated by respective transmit channels of a MRI apparatus into respective standardized maps; and b) determining RF waveforms (P) minimizing a discrepancy between subject-specific distributions of flip-angles of nuclear spin and a target distribution, averaged over said subjects, the subject-specific distributions corresponding to the flip-angle distributions achieved by applying a superposition of RF fields, each having a temporal profile described by one of said RF waveforms and a spatial amplitude distribution described by a respective standardized map determined for the subject. A method and an apparatus for performing parallel-transmission MRI using such a pulse sequence are provided.
Magnetic resonance imaging apparatus and SAR evaluation apparatus
A magnetic resonance imaging apparatus according to the present embodiment includes processing circuitry and imaging control circuitry. The processing circuitry selects a human body model corresponding to a subject from human body models. The processing circuitry estimates local specific absorption rates (SARs) at evaluation points determined using the selected human body model, based on the selected human body model and an amplitude and/or phase of the RF pulse in an imaging protocol for magnetic resonance imaging scheduled to be performed on the subject. The processing circuitry determines whether or not the estimated local SARs fall below a local reference value. The imaging control circuitry executes the imaging protocol by using an amplitude and phase of the RF pulse which make the local SARs fall below the local reference value.