Patent classifications
G01R33/5605
NON-INVASIVE PH-DEPENDENT IMAGING USING QUANTITATIVE CHEMICAL EXCHANGE SATURATION TRANSFER (QCEST)
In various embodiments, the invention teaches systems and methods for magnetic resonance imaging. In some embodiments, the invention teaches systems and methods for determining the source of pain in intervertebral discs by measuring one or more physiological biomarkers associated with disc pain and/or disc degeneration.
Motion detection in CEST magnetic resonance imaging based on Z-spectrum analysis
A medical imaging system includes a memory for storing machine executable instructions. The medical imaging system further includes a processor for controlling the medical imaging system. Execution of the machine executable instructions causes the processor to: receive magnetic resonance image data acquired according to a CEST magnetic resonance imaging protocol, wherein the magnetic resonance image data includes voxels, wherein each of the voxels includes a measured Z-spectrum for a set of saturation frequency offsets; assign a motion likelihood map to each voxel by comparing the measured Z-spectrum of each voxel to predetermined criteria; and reconstruct a CEST magnetic resonance image using the magnetic resonance image data and the motion likelihood map.
Systems and methods for utilizing periodic irradiation to enhance sensitivity of magnetic resonance detection
The present disclosure provides a method for using a magnetic resonance system to measure magnetization data from a region of interest in a subject having a spin system that includes at least a first labile spin species and a second labile spin species experiencing chemical exchange. The method includes applying periodic radiofrequency irradiation to the spin system using a frequency swept pulse sequence having frequency and amplitude modulation functions, wherein sweeping a frequency of the RF irradiation together with amplitude modulation generates a magnetic field component having an effective field. The method further includes generating off resonance side bands in a frequency domain positioned adjacent the resonant frequency of the first labile spin species or the second labile spin species by applying the periodic RF irradiation to induce the instantaneous flip of the effective field with periodicity of RF irradiation tuned to the chemical shift difference of the exchanging sites.
MEDICAL DATA PROCESSING APPARATUS, MEDICAL DATA PROCESSING METHOD, AND MAGNETIC RESONANCE IMAGING APPARATUS
According to one embodiment, a medical data processing apparatus includes processing circuitry. The processing circuitry acquires imaging data acquired by executing spoiled gradient echo imaging and coherent gradient echo imaging by using multiple flip angles. The processing circuitry generates a low-rank approximate image set, which is a set of low-rank approximated images from the imaging data. The processing circuitry reconstructs one or more parameter maps using the above low-rank approximate image set and a related to water exchange in a biological tissue, the multi-pool model including plural free waters and bound water that performs magnetization exchange with those free waters.
METHOD AND SYSTEM FOR IMPROVING THE CONTRAST OF MAGNETIZATION-TRANSFER-PREPARED MRI
In a method for improving the contrast of magnetization-transfer-prepared magnetic resonance imaging (MRI), an acquisition scheme comprising a plurality of inversion-recovery (IR)-imaging modules in an interleaved arrangement is selected, a number of magnetization-transfer (MT)-preparation modules is selected, a pulse sequence is generated by arranging at least one MT-preparation module of the number of MT-preparation modules between two successive IR-preparation modules of the interleaved IR-imaging modules or in front of the first IR-preparation module of a group of interleaved IR-imaging modules, and the pulse sequence for an MRI examination is applied or saved. Each IR-imaging module may include an IR-preparation module and a slice acquisition module.
DOUBLE OFFSETS AND POWERS MAGNETIZATION TRANSFER RATIO FOR SPECIFIC MAGNETIZATION TRANSFER MAGNETIC RESONANCE IMAGING
Imaging methods for assessing the macromolecular content, such as myelin, are of great interest for understanding brain tissue microstructure, and have shown potentials in diagnosing and prognosing demyelinating diseases. for example. Magnetization transfer (MT) is a MRI contrast mechanism that enables detection of macromolecules. Previously, the MT effect has been analyzed by a semi-quantitative method termed magnetization transfer ratio (MTR) or by a quantitative magnetization transfer (qMT) method. However, because MTR does not have enough sensitivity and specificity to myelin, and qMT takes a very long scan time, their translation into clinical scenarios has been limited. This disclosure describes a MT data analysis metric using double saturation pulse offsets and powers (dopMTR). Simulations and experiments using the systems and methods described in this disclosure show that the dopMTR yields much better sensitivity and specificity to MT effect than the conventional MTR, and requires much less scan time than the qMT.
MAGNETIC RESONANCE APPARATUS
A magnetic resonance imaging apparatus comprises a scanning unit for performing a pulse sequence PS including a MT (Magnetization Transfer) pulse b for lessening signals from the cerebral parenchyma (white matter and gray matter). The scanning unit performs the pulse sequence PS in periods of time P1 and P3 in the pulse sequence PS so that the MT pulse b is applied every repetition time TR, while it performs the pulse sequence PS in a period of time P2 in the pulse sequence PS so that no MT pulse b is applied.
SYSTEM AND METHOD FOR CHEMICAL SHIFT MAGNETIC RESONANCE IMAGING USING MAGNETIZATION TRANSFER
A system and method is provided for producing a map of a static magnetic field (B.sub.0) of a magnetic resonance imaging system. The method includes forming a first dataset by acquiring, with the MRI system, a first plurality of different echo signals occurring at a respective plurality of different echo times. The method also includes forming a second dataset by acquiring, with the MRI system, a second plurality of different echo signals occurring at a respective plurality of different echo times. The second dataset includes signals resulting from a magnetization transfer (MT) between free water and bound molecules. The method further includes generating MT-weighted maps using the first dataset and the second dataset, determining, using the MT-weighted maps, a phase difference between the first plurality of different echo signals, and using the phase differences, generate a corrected map of the static magnetic field (B.sub.0) of the MRI system.
Quantifying breast tissue changes with spectrally selective MRI and MRS
Systems and methods for magnetic resonance analysis and imaging are provided. IN particular, pulse sequences for DWI, APT, and MRS analysis and imaging are provided which rely on an RF excitation pulse for the signal of interest, followed by one or more refocusing pulses and acquisition steps, based on the type of imaging.
DNP apparatus
A DNP apparatus includes a cryostat (7) having an opening (8) and a loading path for a sample (1), the loading path extending from the opening to a sample receptacle (29), with a cryomagnet and a microwave source (2) as well as a configuration for supplying microwave radiation from the microwave source to the sample, which comprises a microwave path extending directly to the sample. The microwave path extends spatially separately from the loading path and the configuration for supplying microwave radiation has at least one microwave feed-through passing through one or more walls of the cryostat. The microwave path is incident on the sample from a direction opposite to the loading path or from a sideward direction at right angles to or at an inclination with respect to the axis of the loading path. This leads to simple and efficient polarization of the electron spins in the sample.