21 results about "Inversion pulse" patented technology

A signal receiving circuit includes first to third pulse generators; and a clock signal recovery unit 100 for generating a recovery clock signal RCLK and a recovery clock delay signal RCLKD, which is a signal obtained by delaying the recovery clock signal as much as a first delay time, using at least one of pulses including a first pulse, a second pulse, a third pulse, and first to third inversion pulses, wherein the clock signal recovery unit includes: a loop interruption circuit including an input node and an output node and turned on and off by at least one of the pulses; and a delay circuit having an input terminal connected to the output node and an output terminal connected to the input node. A signal value of the input node and a signal value of the output node are in an inverse relationship.

This application provides an inertial measurement method and system based on atomic interferometry. The method includes: controlling a first atomic beam and a second atomic beam to exit into an interference region, and sequentially interacting with three pulse beams in the interference region to detect the corresponding momentum transfer probability signals. The exit directions of the first and second atomic beams intersect and are symmetrical about the quantization axis. The effective pulse vector directions of the three pulse beams are adjusted so that the adjusted effective pulse vector directions are opposite to those of the original three pulse beams. The first and second atomic beams are then controlled to exit into the interference region, and sequentially interact with the adjusted three pulse beams in the interference region to detect the corresponding momentum transfer probability signals. Based on the four momentum transfer probability signals, the inertial measurement result is determined. Thus, by reversing the effective pulse vector direction, the interference area is reversed, effectively suppressing noise and drift terms unrelated to the effective pulse vector direction.

The present invention provides a magnetic resonance imaging apparatus and a control method thereof. Even when parallel imaging is employed for imaging using a spin-echo pulse sequence, artifacts caused by FID signals are suppressed. When executing a spin-echo pulse sequence using an excitation RF pulse to excite nuclear spins and an inversion RF pulse to invert the excited nuclear spins as high-frequency magnetic field pulses, the high-frequency transmitting unit of the MRI apparatus changes the phase of the inversion RF pulse according to the phase encoding and the number of phase encodings assigned to each echo signal. Specifically, the phase of the inversion RF pulse is controlled to be a quadratic function of the phase encoding of the echo signal.

The invention relates to magnetic resonance, MR, imaging, comprising: subjecting one portion of an object (10) to a preparation sequence (PRE) comprising a spectrally selective adiabatic inversion radiofrequency, RF, pulse (21) having a flip angle (a) to selectively invert nuclear magnetization associated with fat protons; after a delay time (TD), subjecting the portion to an imaging sequence (IM) comprising one excitation RF pulse (28) to generate MR signals (27), wherein the delay time and / or the flip angle are determined such that contributions from a first spectral species of fat protons affected by the inversion RF pulse and a second spectral species of fat protons not affected by the inversion RF pulse to the MR signals substantially cancel each other out; acquiring the MR signals; and reconstructing an MR image from the MR signals, wherein contributions from both the first and second spectral species of fat protons are suppressed in the MR image.

The invention discloses a low-field NMR relaxation time rapid measurement method, and the method comprises the steps: designing an IR-bSSFP pulse sequence which comprises a 180-degree reversal pulse and an excitation pulse sequence, and enabling the flip angle of a radio frequency excitation pulse in the excitation pulse sequence to be a pseudo-random flip angle; the radio-frequency phases of the adjacent radio-frequency excitation pulses are linearly changed by a fixed phase increment; based on the IR-bSSFP pulse sequence, obtaining a component MRF signal sequence of a measured object, and simulating a magnetization vector evolution process to obtain a dictionary matrix; matching the component MRF signal with a dictionary matrix pattern in combination with a smooth constraint term to obtain corresponding longitudinal relaxation time and transverse relaxation time; the invention also discloses low-field NMR relaxation time rapid measurement equipment, which comprises a pulse sequence construction module, a dictionary generation module and a mode matching module. Multi-parameter information can be obtained through single scanning, the measurement time is remarkably shortened, the experiment complexity is reduced, and the precision and repeatability of a measurement result are improved.

The application relates to a method for determining inversion time in blood vessel imaging, a magnetic resonance imaging method and a device. The method for determining inversion time in blood vessel imaging comprises the following steps: selecting an imaging position from a blood vessel imaging area; at the imaging position, collecting at least two blood vessel images with different inversion times by using an inversion time searching technology; obtaining an inversion time corresponding to a blood vessel image with optimal blood vessel display; and determining a time point for setting a longitudinal magnetization to zero according to the inversion time corresponding to the blood vessel image with optimal blood vessel display. The magnetic resonance imaging method comprises the following steps: determining an inversion time based on the method for determining inversion time in blood vessel imaging; applying a regional selection inversion pulse at an imaging position; and applying a target imaging sequence at the imaging position after the inversion time to obtain a target magnetic resonance image. The method can optimize the inversion time, thereby obtaining optimal blood vessel display.

The invention relates to a method for improving the scanning speed of an SPAIR (Space Polycyclic Amplified Impulse Response) fat suppression sequence. The method comprises the following steps: designing SPAIR fat suppression pulses; the method is applied to an SPAIR fat pressing sequence, a control pulse only turns over a fat signal, the interval between an adiabatic pulse and a water signal excitation pulse is adjusted, and the effect of reducing scanning time is achieved. Before formal data acquisition, adiabatic inversion pulses need to be excited several times to enable fat signals to reach a steady state, then data acquisition is carried out, and part of acquired data is prevented from containing the fat signals. According to the method, by means of a recovery mechanism of the SPAIR fat signal, the fat signal of the SPAIR fat signal gradually approaches a steady-state value through multiple times of pre-scanning adiabatic inversion pulses, the zero crossing point time of the SPAIR fat signal is shortened, and the scanning speed of the SPAIR sequence is increased.

A qMRI system and method map qMRI parameters of a biological object. The method includes performing, by the qMRI system, N scans wherein each scan, includes: performing T2-prepared inversion pulse series, each followed by readout blocks, each magnetization preparation RF pulse series is a T2-prepared inversion pulse series containing multiple pulses and an inter-pulse duration, for varying to obtain different T2 weightings; and acquiring, by the MRI system and during each readout block of an MRI, a recovery signal generated by a part of the biological object, wherein for each readout block, an MRI signal is acquired by the MRI system at different inversion times. An image of the part is reconstructed for and from each MRI signal. A voxel-wise signal is created by concatenating intensity values for a same voxel for the reconstructed images. A physical model is fitted to the concatenated intensity values to obtain a qMRI map.

The invention relates to a method of MR imaging. It is an object of the invention to provide an improved B1 mapping method that is less affected by T1 relaxation. The invention proposes that a first stimulated echo imaging sequence (25) is generated comprising at least two preparation RF pulses (α) radiated during a first preparation period (21) and a sequence of reading RF pulses (β) radiated during a first acquisition period (22) temporally subsequent to the first preparation period (21). A first set of FID signals (IFID) and a first set of stimulated echo signals (ISTE) are acquired during the first acquisition period (22). A second stimulated echo imaging sequence (27) is generated comprising again at least two preparation RF pulses (α) radiated during a second preparation period (21) and a sequence of reading RF pulses (β) radiated during a second acquisition period (22) temporally subsequent to the second preparation period (21). A second set of FID signals (IFID) and a second set of stimulated echo signals (ISTE) are acquired during the second acquisition period (22). The first and second sets of FID signals (IFID) have different T1-weightings and / or the first and second sets of stimulated echo signals (ISTE) have different T1-weightings. A B1 map indicating the spatial distribution of the RF field of the RF pulses is derived from the acquired first and second sets of FID (IFID) and stimulated echo (ISTE) signals, wherein the different T1-weightings are made use of to compensate for influences on the B1 map caused by T1 relaxation. Preferably, either the first or the second preparation period (21) is preceded by an RF inversion pulse to obtain the different T1-weightings. Moreover, the invention relates to an MR device (1) and to a computer program for an MR device (1).

The invention provides a magnetic resonance angiography method and magnetic resonance imaging equipment. The method comprises the following steps: for each magnetic resonance image to be generated in a magnetic resonance image sequence, sequentially generating a layer selection saturation pulse signal and N reversal pulse signals in an imaging area of at least a target object; magnetic resonance signals of tissue in the imaging region are acquired and the magnetic resonance image is generated based on the acquired magnetic resonance signals. The longitudinal magnetization directions of the blood subjected to the second reversal operation in the first time period are negative when the blood is imaged in the imaging area, and the longitudinal magnetization directions of the blood subjected to the second reversal operation in the second time period are positive when the blood is imaged in the imaging area. The display effect of the blood inflow process in the obtained magnetic resonance image sequence is clearer, and a user can be helped to determine the actual condition of blood perfusion into the blood vessel in the imaging area.

Systems, computer-implemented methods, and / or computer program products that can facilitate target qubit decoupling in an echoed cross-resonance gate are provided. According to an embodiment, a computer-implemented method can comprise receiving, by a system operatively coupled to a processor, both a cross-resonance pulse and a decoupling pulse at a target qubit. The cross-resonance pulse propagates to the target qubit via a control qubit. The computer-implemented method can further comprise receiving, by the system, a state inversion pulse at the control qubit. The computer-implemented method can further comprise receiving, by the system, both a phase-inverted cross-resonance pulse and a phase-inverted decoupling pulse at the target qubit. The phase-inverted cross-resonance pulse propagates to the target qubit via the control qubit.

The application provides a magnetic resonance angiography method and a magnetic resonance imaging device, the magnetic resonance angiography method comprising: for each magnetic resonance image to be generated in a magnetic resonance image sequence, sequentially generating a layer selection saturation pulse signal and N inversion pulse signals in a preset time period corresponding to the magnetic resonance image and in at least an imaging region of a target object, the N inversion pulse signals being used for performing a first inversion operation on tissues in the at least imaging region; after or simultaneously with performing the first inversion operation on the tissues in the at least imaging region by using an (N-i+1)th inversion pulse signal, and before performing the first inversion operation on the tissues in the at least imaging region by using an (N-i)th inversion pulse signal, performing a second inversion operation on blood in a labeling region; collecting a magnetic resonance signal of the tissues in the imaging region, and generating the magnetic resonance image. In the above scheme, the total time consumption of the magnetic resonance imaging process is shorter, and the imaging efficiency is significantly improved.

The invention relates to the technical field of medical image diagnosis, in particular to a black blood T2 weighted fast spin echo imaging method and system under a free breathing condition. According to the black blood imaging method based on reverse dual inversion recovery (RDIR) and single excitation fast spin echo (SS-FSE), artificial intelligence assisted compressed sensing (ACS) is introduced to improve the reconstruction quality. The slice selective reversal pulse is moved forward to the previous cardiac cycle, so that myocardial signal loss is effectively reduced; scanning time can be remarkably shortened and motion artifacts can be reduced by adopting single excitation. And in combination with the ACS, a high-resolution T2 weighted black blood image can be obtained under high and under-sampling conditions, and the method is particularly suitable for edema evaluation of children under free breathing.

The invention relates to magnetic resonance, MR, imaging, comprising: subjecting one portion of an object (10) to a preparation sequence (PRE) comprising a spectrally selective adiabatic inversion radiofrequency, RF, pulse (21) having a flip angle (a) to selectively invert nuclear magnetization associated with fat protons; after a delay time (TD), subjecting the portion to an imaging sequence (IM) comprising one excitation RF pulse (28) to generate MR signals (27), wherein the delay time and / or the flip angle are determined such that contributions from a first spectral species of fat protons affected by the inversion RF pulse and a second spectral species of fat protons not affected by the inversion RF pulse to the MR signals substantially cancel each other out; acquiring the MR signals; and reconstructing an MR image from the MR signals, wherein contributions from both the first and second spectral species of fat protons are suppressed in the MR image.

Disclosed herein is an MRI system (100) configured for acquiring MRI data (414) and a method of processing the MRI data. The MRI system (100) comprises a computational system (400) configured to control the MRI system (100) with pulse sequence commands (412) to acquire the MRI data (414) for a plurality of saturation frequencies (416). For a partial inversion pulse of the SPIR a varying flip angle is used, which is varied depending on the saturation frequencies (416) being used.

The invention provides a magnetic resonance blood imaging method, magnetic resonance blood imaging equipment and a nonvolatile storage medium. The method comprises the following steps: generating a layer selection saturation pulse signal in an imaging area; n inversion pulse signals are sequentially generated in the imaging area so as to perform first inversion operation on the tissue in the imaging area, and after or at the same time of performing the first inversion operation on the tissue in the imaging area by using the (i + 1)-th inversion pulse signal in the N inversion pulse signals, the (i + 1)-th inversion pulse signal in the N inversion pulse signals is converted into the (i + 1)-th inversion pulse signal, before the first inversion operation is carried out on the tissue in the imaging area by utilizing the inverse ith inversion pulse signal in the N inversion pulse signals, the second inversion operation is carried out on the blood in the marking area, and i is a positive odd number smaller than N; magnetic resonance signals of the tissue in the imaging region are acquired and a magnetic resonance image is generated. The total time consumption of imaging is shorter, and the generation efficiency of the magnetic resonance image is improved. And moreover, the influence of the pose of the target object on the contrast of the magnetic resonance image can be reduced.

Disclosed herein is an MRI system (100) configured for acquiring MRI data (414) and a method of processing the MRI data. The MRI system (100) comprises a computational system (400) configured to control the MRI system (100) with pulse sequence commands (412) to acquire the MRI data (414) for a plurality of saturation frequencies (416). For a partial inversion pulse of the SPIR a varying flip angle is used, which is varied depending on the saturation frequencies (416) being used.

The present application relates to a method, a calculation method and a system for rapid in-vivo imaging of blood T1 and T2. The imaging method includes several rounds of processes of exciting and sampling an imaging acquisition area including a cross-section of the sagittal sinus. The imaging acquisition area includes a front-end venous blood labeling layer block and a rear-end venous blood image layer block. Each sampling process includes: alternately exciting the corresponding layer block area with a T1b imaging method and a T2b imaging method and sampling a T1b sampling image and a T2b sampling image; both the T1b imaging method and the T2b imaging method in each sampling process are repeated twice, and the two T2b imaging methods respectively use an inversion pulse signal for slice-selective excitation and non-slice-selective excitation of the front-end venous blood labeling layer block to obtain a labeled and controlled image of the rear-end venous blood image layer block. The sequence of the present application is flexible and can control the total sampling time within 25 seconds. The simultaneously obtained T1b does not depend on the repeated sampling time of T2b and can reduce the systematic deviation of T2b through optimized fitting.

The invention provides a magnetic resonance imaging method and magnetic resonance imaging equipment, and the method comprises the steps: for each to-be-generated magnetic resonance image in a magnetic resonance image sequence, in a preset time period corresponding to the magnetic resonance image and in an imaging region of at least a target object, carrying out the magnetic resonance imaging on the target object; sequentially generating a layer selection saturation pulse signal and N reversal pulse signals, wherein the N reversal pulse signals are used for performing first reversal operation on tissue in at least the imaging area; after or at the same time as performing the first inversion operation on the tissue in at least the imaging region by using the reciprocal (i + 1) th inversion pulse signal, and before performing the first inversion operation on the tissue in at least the imaging region by using the reciprocal ith inversion pulse signal, performing a second inversion operation on the blood in the marked region; magnetic resonance signals of tissue in the imaging region are acquired and a magnetic resonance image is generated. According to the scheme, the total consumed time of the magnetic resonance imaging process is shorter, and the imaging efficiency is remarkably improved.

An electronic device includes: a sensor layer including a plurality of electrodes arranged in “n” rows and “m” columns; and a sensor driver configured to drive the sensor layer, and wherein the plurality of electrodes include: a plurality of electrodes configured to receive a driving pulse signal located within one of the “m” columns; and a plurality of inversion electrodes configured to receive an inversion pulse signal different from the driving pulse signal, and wherein the sensor driver is configured to determine a number of the plurality of inversion electrodes based on a location of the plurality of electrodes, and wherein, the “n” and the “m” are natural numbers.