Patent classifications
G01R33/56341
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.
STIMULATED ECHO SEQUENCE SCANNING MAGNETIC RESONANCE METHOD AND APPARATUS FOR HEART DIFFUSION IMAGING
In a method and magnetic resonance (MR) apparatus for heart diffusion imaging, when an ECG trigger signal by a computer that operates an MR scanner, the MR scanner is operated to acquire a navigator echo before a stimulated echo sequence, in order to detect diaphragm position information. When the first diaphragm position information is not located in an acquisition window, the stimulated echo sequence is not executed, and the computer waits to receive the next ECG trigger signal. The detection time of the navigator echo after the stimulated echo sequence as well as the acquisition time of the stimulated echo sequence, are thus eliminated when the first diaphragm position information does not meet requirements, so can significantly reduce scanning time, and increase the image SNR.
Method and apparatus for acquiring a high-resolution magnetic resonance image dataset of at least one limited body region having at least one anatomical structure of a patient
In a method and magnetic resonance apparatus for acquiring a high-resolution magnetic resonance image dataset of at least one limited body region having at least one anatomical structure of a patient, an overview image dataset is first acquired, using which an item of position information of the at least one anatomical structure is ascertained, the item of position information designating an exact position of the at least one anatomical structure and/or a relative position of the at least one anatomical structure relative to the reference body region. A high-resolution magnetic resonance image dataset of the anatomical structure is then created using the position information and the high-resolution magnetic resonance image dataset is evaluated. The evaluated high-resolution image data is then made available in electronic form.
Measuring blood vessel characteristics with MRI
Aspects of the subject disclosure may include, for example, obtaining first magnetic resonance imaging (MRI) data of a subject, wherein the first MRI data is obtained during a first scan of a subject, wherein the first scan has a first diffusion sampling time, and wherein the first diffusion sampling time is selected in order to facilitate use of the first MRI data to determine a first Intravoxel Incoherent Motion (IVIM) effective diffusion coefficient in a Stationary Random Flow (SRF) regime; obtaining second MRI data of the subject, wherein the second MRI data is obtained during a second scan of the subject, wherein the second scan has a second diffusion sampling time, wherein the second diffusion sampling time is longer than the first diffusion sampling time, and wherein the second diffusion sampling time is selected in order to facilitate use of the second MRI data to determine a second IVIM effective diffusion coefficient in a pseudodiffusion regime; determining a blood velocity value based upon the first MRI data; and determining a segment length value based upon the second MRI data. Additional embodiments are disclosed.
Magnetic resonance imaging apparatus and control method for the same
A magnetic resonance imaging system adaptively and dynamically adjusts color and brightness of illuminators mounted on the inside of a bore in response to a scan sequence used for magnetic resonance imaging or the state of a patient in order to relieve discomfort during magnetic resonance imaging. An illuminator control unit selects and determines optical characteristics of the illuminators in response to a scan sequence or the state of a patient.
MRI-BASED FEEDBACK CONTROL OF ULTRASOUND BASED MECHANICAL FRACTIONATION OF BIOLOGICAL TISSUE
Disclosed herein are example embodiments of devices, systems, and methods for mechanical fractionation of biological tissue using magnetic resonance imaging (MRI) feedback control. The examples may involve displaying an image representing first MRI data corresponding to biological tissue, and receiving input identifying one or more target regions of the biological tissue to be mechanically fractionated via exposure to first ultrasound waves. The examples may further involve applying the first ultrasound waves and, contemporaneous to or after applying the first ultrasound waves, acquiring second MRI data corresponding to the biological tissue. The examples may also involve determining, based on the second MRI data, one or more second parameters for applying second ultrasound waves to the biological tissue, and applying the second ultrasound waves to the biological tissue according to the one or more second parameters.
MR ELECTRIC PROPERTIES TOMOGRAPHY WITHOUT CONTRAST AGENT
The invention relates to a method of MR imaging of an object (10) placed in an examination volume of a MR device (1). It is an object of the invention to enable MR signal acquisition in a single scan providing the necessary information for electric properties imaging (EPT), namely a phase map as well as tissue boundaries. The method of the invention comprises the following steps: —subjecting the object (10) to a multi echo steady state imaging sequence or a fast spectroscopic imaging sequence comprising RF pulses and switched magnetic field gradients, wherein two or more echo signals are generated after each RF excitation; —acquiring the echo signals; —deriving a magnitude image and a phase map from the acquired echo signals, which phase map represents the spatial RF field distribution induced by the RF pulses in the object (10); and —reconstructing an electric conductivity map from the magnitude image and from the phase map, wherein tissue boundaries are derived from at least the magnitude image. Moreover, the invention relates to a MR device for carrying out this method as well as to a computer program to be run on a MR device.
METHOD FOR OPTIMIZED BIAS AND SIGNAL INFERENCE IN MAGNETIC RESONANCE IMAGE ANALYSIS
An approach to estimate noise, Rician signal bias and true signal in magnitude signal data obtained with magnetic resonance imaging. The method uses multiple measurements at different scan parameter settings, also referred to as weightings, and an iterative algorithm to estimate noise, expected signal and associated Rician signal bias. Measurements at all measured weighting levels contribute to the ultimate estimation of the bias-free signal decay function. Therefore, of the so processed magnetic resonance image data, weighted signals can be computed at arbitrary weighting levels and with considerably better signal-to-noise ratio than the originally obtained data at corresponding weightings. Bias-free weighted image data at desired weighting levels, maps of the decay function fit parameters, or maps of a combination of such decay function parameters can be used for rapid and highly sensitive tissue characterization.
METHOD, CONTROLLER, AND MAGNETIC RESONANCE APPARATUS FOR MODEL-FREE DETERMINATION OF IMAGE REGIONS WITH ANOMALOUS DIFFUSION USING DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGE DATA
In a magnetic resonance apparatus and a method and controller for operating such an apparatus, first and second diffusion-weighted image data are reconstructed from first and second diffusion-encoded raw data that were respectively acquired using different diffusion-encoding gradient pulse sub-sequences. The different sub-sequences differ by respectively having a different parameter that characterizes the respective sub-sequence as a function of time. The first and second reconstructed image data are compared and a deviation of the image data from normal Gaussian diffusion behavior is determined model-free on the basis of the comparison result.
Imaging nerve function and pathologies using diffusion basis spectrum imaging
Repetitive electrical activity produces microstructural alteration in myelinated axons. These transient microstructural changes can be non-invasively visualized via two different magnetic-resonance-based approaches: diffusion fMRI and dynamic T.sub.2 spectroscopy in the ex vivo perfused bullfrog sciatic nerves. Non-invasive diffusion fMRI, based on standard diffusion tensor imaging (DTI), clearly localized the sites of axonal conduction blockage as might be encountered in neurotrauma or other lesion types. Diffusion fMRI response was graded in proportion to the total number of electrical impulses carried through a given locus. Diffusion basis spectrum imaging (DBSI) method revealed a reversible shift of tissue water into a restricted isotropic diffusion signal component, consistent with sub-myelinic vacuole formation.