Patent classifications
G01R33/4822
System and method for controlling physiological noise in functional magnetic resonance imaging
A system and method is provided for controlling physiological-noise in functional magnetic resonance imaging using raw k-space data to extract physiological noise effects. The method can identify these effects when they are separable and directly reflects the artefactual effects on fMRI data, without the need for external monitoring or recording devices and to be compensated for via rigorous statistical analysis modeling of such noise sources. The physiological fluctuations may be treated as global perturbations presented around the origin point in a k-space 2D slice. Each k-space 2D slice may be acquired at a very short repetition time with an effective sampling rate to sample cardiac and respiratory rhythms through proper reordering and phase-unwarping techniques applied to the raw k-space data.
MAGNETIC RESONANCE IMAGING APPARATUS AND MAGNETIC RESONANCE IMAGING METHOD
A magnetic resonance imaging apparatus includes sequence controlling circuitry and processing circuitry. The sequence controlling circuitry executes (i) a first pulse sequence in which a spatially selective Inversion recovery (IR) pulse and a spatially non-selective IR pulse are applied, and (ii) a second pulse sequence in which the spatially non-selective IR pulse is applied without applying the spatially selective IR pulse, while varying the first TI period, with respect to a plurality of first TI periods. The sequence controlling circuitry executes (iii) the third pulse sequence in which the spatially selective IR pulse and the spatially non- selective IR pulse are applied, and (iv) the fourth pulse sequence in which the spatially non-selective IR pulse is applied without applying the spatially selective IR pulse. The processing circuitry generates a magnetic resonance image of an imaged region based on data obtained from the third pulse sequence and the fourth pulse sequence.
Method for postural independent location of targets in diagnostic images acquired by multimodal acquisitions and system for carrying out the method
A method for postural independent location of targets in diagnostic images acquired by multimodal acquisitions, compensating for deformation of soft tissues due to changing posture, includes generating a transition of a digital image of the inside of a target region from a first to a second position by correlating the position of markers placed on the external surface of the target region in a digital image of the inside of the target region and in a digital representation of the external surface of the target region acquired by optically scanning the external surface; and at a later time registering the diagnostic image of the inside of the target region, transitioned into the second position, with a diagnostic image of the same target region acquired with the target region in the second position by matching a second representation of the external surface of the target region in the second position without markers with the diagnostic image of the inside of the target region transitioned into the second position.
3D flow compensated interleaved epi in combination with swapped readout
The disclosure relates to a fast susceptibility imaging techniques for performing flow compensations in the slice, phase, and frequency encoding directions for the central echo of a plurality of echoes excited each time in interleaved echo planar imaging (iEPI). The echo data for which flow compensations have been performed may be collected, and susceptibility-weighted imaging (SWI) performed for collected echo data. The fast susceptibility imaging techniques may reduce scan time.
Real-time generation of MRI slices
A method includes displaying a position of a distal end of a medical probe that is being navigated in an organ of a patient on a three-dimensional (3D) map of the organ. In response to an event, a plane of interest including the distal end is selected, a real-time Magnetic Resonance Imaging (MRI) slice of the organ is acquired at the selected plane, and the MRI slice is displayed overlaid on the 3D map.
Optimization of the noise development of a 3D gradient echo sequence in a magnetic resonance system
In a method according to optimize the noise development of a 3D gradient echo sequence in a magnetic resonance system, an optimization of at least one parameter of the gradient echo sequence, from the group including: the excitation pulse (the duration of the excitation pulse); the order of k-space lines to be scanned in k-space; and the readout direction of the k-space lines to be scanned in k-space, is implemented such that the gradients to be switched have optimally minimal slew rates, amplitudes and/or polarity changes.
QUIET MRI USING ALTERNATING GRADIENT SEQUENCE
Magnetic resonance imaging (MRI) systems and methods to effect MRI data acquisition with reduced noise are described. A readout gradient, having a first polarity used to acquire and store MRI data in k-space memory during analog-to-digital conversion (ADC) of MR RF signals during one TR interval, is continued at substantially a same amplitude and vector direction and used as an image volume selection gradient during a transmitted RF excitation pulse that begins a next TR interval before the readout gradient transitions to an opposite polarity. The acquired k-space data is then used to generate an MR image.
QUIET MRI WITH SPIN ECHO (SE) OR FAST SPIN ECHO (FSE)
Magnetic resonance imaging (MRI) systems and methods to effect MRI data acquisition with reduced noise in fast spin echo (FSE) and spin echo (SE) implementations are described. The improved MRI data acquisition is performed by acquiring k-space data while maintaining a constant or near constant slice select gradient amplitude throughout a sequence kernel. The acquired k-space data can then be used to generate an MR image.
Magnetic resonance imaging apparatus configured to acquire target site diagnostic image data based on detection of target sites in prior acquired image data
A magnetic resonance imaging apparatus according to an embodiment includes a specifying unit and an acquiring unit. The specifying unit specifies, on a basis of a detection result of target sites of a subject detected from an image on which the target sites are visualized, a first region and a second region which is different from the first region on the image. The acquiring unit acquires data of the second region by using an imaging condition which is different from an imaging condition on an imaging slice and used for acquiring data of the first region.
System and method for free-breathing volumetric imaging of cardiac tissue
A magnetic resonance imaging (MRI) system and methods are provided for producing images of a subject. In some aspects, a method includes identifying a point in the cardiac cycle, performing an inversion recovery (IR) pulse at a selected time point from the pre-determined point, and sampling a k-space segment at an inversion time from the IR pulse that is substantially coincident with the pre-determined point. The method also includes repeating the IR pulse and k-space sampling for multiple inversion times, and multiple segments of k-space, in an interleaved manner, to generate datasets having T1-weighted contrasts determined by their respective inversion times. The method further includes reconstructing three-dimensional (3D) spatially-aligned images using the datasets, and generating a T1 recovery map by combining the 3D images. In some aspects, a prospective/retrospective scheme may be used to obtain data fully sampled in the center of k-space and randomly undersampled in the outer regions.