Patent classifications
G01R33/4616
MRI using RF gradients for spatial encoding
Systems and methods for performing MRI include using a RF gradient field for spatial encoding. In particular implementations, |B.sup.+.sub.i|-selective pulses designed using the Shinnar-Le Roux algorithm can be provided as the excitation pulse for the RF gradient field. Further, frequency encoding for the RF gradient field can be based on the Bloch-Siegert (BS) shift. Together, these techniques can be used to support MRI based on RF gradient encoding instead of the conventional Bo encoding.
MAGNETIC RESONANCE IMAGING (MRI) SYSTEMS AND METHODS USING ADIABATIC TIP-DOWN AND MATCHED ADIABATIC FLIP-BACK PULSES
Magnetic resonance imaging (MRI) systems and methods using adiabatic tip-down and matched adiabatic flip-back pulses are disclosed. According to an aspect, a system includes a signal generator configured to generate a pulse sequence for on-resonance magnetization transfer preparation. The pulse sequence includes an adiabatic tip-down pulse and a matched adiabatic flip-back pulse for separating spins in a mobile spin pool from spins in a bound spin pool of an anatomical region of interest for imaging. The system includes radio frequency (RF) coils configured to transmit RF pulses in response to the pulse sequence and to acquire RF data in response to transmission of the RF pulses. Further, the system includes a processing system configured to process the RF data to provide a display image indicating different tissue types with discrimination.
MAS STATOR OF AN NMR PROBE HEAD WITH OPTIMIZED MICROWAVE IRRADIATION
An NMR probe head with an MAS stator (1) supplied with microwave radiation from a microwave guide (9) through an opening in a coil block (2) has a microwave lens (6) and a microwave mirror (8a) on an inner side of the MAS stator. The MAS rotor (3) is surrounded by a solenoid RF coil (5) and the microwave lens is arranged and embodied in the opening of the coil block on the side facing a sample volume (4) such that the cylinder axis of the MAS rotor lies in the focus of the microwave lens. The microwave mirror is arranged on, or in, the inner wall of the MAS stator that lies opposite the microwave guide and has a cylindrical and concave structure, such that the microwave mirror focuses the microwave radiation incident from the sample volume onto the central axis of the MAS rotor.
Use of nuclear spin impurities to suppress electronic spin fluctuations and decoherence in composite solid-state spin systems
A solid state electronic spin system contains electronic spins disposed within a solid state lattice and coupled to an electronic spin bath and a nuclear spin bath, where the electronic spin bath composed of electronic spin impurities and the nuclear spin bath composed of nuclear spin impurities. The concentration of nuclear spin impurities in the nuclear spin bath is controlled to a value chosen so as to allow the nuclear spin impurities to effect a suppression of spin fluctuations and spin decoherence caused by the electronic spin bath. Sensing devices such as magnetic field detectors can exploit such a spin bath suppression effect, by applying optical radiation to the electronic spins for initialization and readout, and applying RF pulses to dynamically decouple the electronic spins from the electronic spin bath and the nuclear spin bath.
Magnetic resonance imaging (MRI) system and method integrating multi-nuclide synchronous imaging and spectral imaging
A magnetic resonance imaging (MRI) system and method integrating multi-nuclide synchronous imaging and spectral imaging is provided. The MRI system includes a spectral imaging module, a multi-nuclide synchronous imaging module, and a spectral reconstruction and image fusion module, where the spectral imaging module is configured to acquire a spectrum of a nuclide Nuc; the multi-nuclide synchronous imaging module is configured to perform synchronous imaging of nuclides Nuc1 . . . Nucn, where when n=1, Nucl is .sup.1H; and when n>1, Nucn is a non-.sup.1H nuclide; and the spectral reconstruction and image fusion module is configured to receive the spectrum of the nuclide Nuc and images of the nuclides Nuc1 . . . Nucn, and acquire spatial distribution information of compounds of the nuclide Nuc and spatial distribution information of the non-.sup.1H nuclide through fusion. The system and method can synchronously acquire MR signals of different nuclides, and reconstruct and fuse non-.sup.1H nuclide images.
USE OF NUCLEAR SPIN IMPURITIES TO SUPPRESS ELECTRONIC SPIN FLUCTUATIONS AND DECOHERENCE IN COMPOSITE SOLID-STATE SPIN SYSTEMS
A solid state electronic spin system contains electronic spins disposed within a solid state lattice and coupled to an electronic spin bath and a nuclear spin bath, where the electronic spin bath composed of electronic spin impurities and the nuclear spin bath composed of nuclear spin impurities. The concentration of nuclear spin impurities in the nuclear spin bath is controlled to a value chosen so as to allow the nuclear spin impurities to effect a suppression of spin fluctuations and spin decoherence caused by the electronic spin bath. Sensing devices such as magnetic field detectors can exploit such a spin bath suppression effect, by applying optical radiation to the electronic spins for initialization and readout, and applying RF pulses to dynamically decouple the electronic spins from the electronic spin bath and the nuclear spin bath.
MAGNETIC COUPLING HIGH RESOLUTION NUCLEAR MAGNETIC RESOLUTION PROBE AND METHOD OF USE
In an embodiment of the invention inductive coupling of an idler coil to a parent coil is used to provide a double resonance circuit without the disadvantages of capacitive coupling to the parent coil. In an embodiment of the invention, an inductive coupling coil can be used to achieve a double-tuned circuit. In an embodiment of the invention, a circuit uses inductive coupling to achieve a double resonance circuit for .sup.1H, .sup.19F, and .sup.13C experiments where one of the three nuclei are observed and the other two are decoupled. In an embodiment of the invention a pivot or a shunt can be used to couple and decouple the idler coil and the parent coil.
SYSTEM AND METHOD FOR MAGNETIC RESONANCE IMAGE ACQUISITION
A system and method of acquiring an image at a magnetic resonance imaging (MRI) system is provided. Accordingly, an analog signal based on a pulse sequence and a first gain is obtained. The analog signal is converted into a digitized signal. A potential quantization error is detected in the digitized signal based on a boundary. When the detection is affirmative, a replacement analog signal based on the pulse sequence is received. At least one portion of the replacement analog signal can be based on an adjusted gain. The adjusted gain is a factor of the first gain. The replacement analog signal is digitized into a replacement digitized signal. At least one portion of the replacement digitized signal corresponding to the at least one portion of the replacement analog signal is adjusted based on a reversal of the factor.
Sideband processing for magnetic resonance
A method includes applying a pulse train to a spin system in a scanner. The pulse train has a plurality of discontinuities in a time domain. The method includes receiving a response from the spin system. The response corresponds to a gated signal. The method includes accessing a correction factor corresponding to the scanner. The method includes calculating a correction to the response based on the correction factor. The method includes generating an output based on the correction.
SIGNAL CODING AND STRUCTURE MODELING FOR IMAGING
A technology is provided for multi-component and/or multi-configuration imaging with coding, signal composition, signal model, structure model, structure model learning, decoding, reconstruction, performance prediction and performance enhancement. A magnetic resonance imaging example comprises acquiring signal samples in accordance with a coding scheme and a k-space sampling scheme, identifying a structure model in a data assembly formed using an extraction operation, and generating a result consistent with both the acquired signal samples and the identified structure model.