G01R33/5619

Multi-echo pseudo-golden angle stack of stars thermometry with high spatial and temporal resolution using k-space weighted image contrast

A method for producing an image of a subject using a magnetic resonance imaging (MRI) system includes acquiring a series of echo signals by sampling k-space along radial lines that each pass through the center of k-space. Each projection of the radial lines is divided into multiple echoes and successive projections are spaced by a predetermined angular distance. The series of echo signals are reconstructed into a plurality of images, wherein each image corresponds to a distinct echo signal.

Selective sampling for assessing structural spatial frequencies with specific contrast mechanisms
10330763 · 2019-06-25 · ·

The disclosed embodiments provide a method for acquiring MR data at resolutions down to tens of microns for application in in vivo diagnosis and monitoring of pathology for which changes in fine tissue textures can be used as markers of disease onset and progression. Bone diseases, tumors, neurologic diseases, and diseases involving fibrotic growth and/or destruction are all target pathologies. Further the technique can be used in any biologic or physical system for which very high-resolution characterization of fine scale morphology is needed. The method provides rapid acquisition of signal at selected values in k-space, with multiple successive acquisitions at individual k-values taken on a time scale on the order of microseconds, within a defined tissue volume, and subsequent combination of the multiple measurements in such a way as to maximize SNR. The reduced acquisition volume, and acquisition of only signal values at select places in k-space, along selected directions, enables much higher in vivo resolution than is obtainable with current MRI techniques.

Method to measure tissue texture using NMR spectroscopy to identify the chemical species of component textural elements in a targeted region of tissue

A method for identifying the chemical species of various textural elements in a targeted region of tissue wherein a volume of interest (VOI) is selectively excited and a k-encode gradient pulse is applied to induce phase wrap to create a spatial encode for a specific k-value and orientation. The specific k-value is selected based on anticipated texture within the VOI. Multiple sequential samples of the NMR RF signal encoded with the specific k-value are recorded as signal data. The Fourier Transform of the acquired signal data is then taken, wherein for each k-encode, the signal recorded is indicative of the spatial frequency power density at that point in k-space. Each peak in the NMR spectrum is then evaluated, whereby the relative contribution to the texture of tissue in the VOI at a k-value for each chemical species is determined.

Method for recording a parameter map by means of a magnetic resonance device, and magnetic resonance device

A method is disclosed for recording a parameter map of a target region via a magnetic resonance device. In at least one embodiment, an optimization method is used for the iterative reconstruction of the parameter map. In the optimization method, the deviation of undersampled magnetic resonance data of the target region present in the k-space for different echo times, magnetic resonance data of a portion of the k-space being present in each case for each echo time, is assessed from hypothesis data of a current hypothesis for the parameter map obtained as a function of the parameter from a model for the magnetization. To determine the magnetic resonance data of a portion of the k-space, undersampled raw data is initially acquired within the portions by way of the magnetic resonance device embodied for parallel imaging, and missing magnetic resonance data within the portions is completed by way of interpolation.

ELASTOGRAPHY IMAGING WITH MAGNETIC RESONANCE IMAGING GUIDED FOCUSED ULTRASOUND

A technology is described for multipoint tissue elastic property measurement. An example method (700) 700 includes generating a treatment map (710) of an anatomical region that shows focal points within the anatomical region to be exposed to Focused Ultrasound (FUS) pulses; acquiring a reference MR-ARFI image (720) of the anatomical region containing the focal points using the treatment map; acquiring an active MR-ARFI image (730) for each of the focal points in the anatomical region during exposure of the focal points to the FUS pulses using the treatment map; interleaving the reference MR-ARFI image and active MR-ARFI images (740) to create a combined image of the anatomical region and the focal points; and calculating a tissue displacement measurement (750) for the focal points exposed to the simultaneous and/or rapidly interleaved FUS pulses using the combined image of the anatomical region and the focal points exposed to the simultaneous FUS pulses.

IMAGING SYSTEMS AND METHODS

An imaging method may include obtaining imaging data associated with a region of interest (ROI) of an object. The imaging data may correspond to a plurality of time-series images of the ROI. The imaging method may also include determining, based on the imaging data, a data set including a spatial basis and one or more temporal bases. The spatial basis may include spatial information of the imaging data. The one or more temporal bases may include temporal information of the imaging data. The imaging method may also include storing, in a storage medium, the spatial basis and the one or more temporal bases.

Magnetic resonance imaging with motion correction suing pre-pulses and navigators

The present invention provides a method for magnetic resonance (MR) imaging of a region of interest (142) of a subject of interest (120) under application of a scanning sequence (200) comprising at least one pre-pulse (202, 204) and multiple readouts (206), whereby the multiple readouts (206) are performed after the at least one pre-pulse (202, 204) with different configurations causing different image contrasts, comprising the steps of performing a preparation phase comprising applying at least one scanning sequence (200) to provide a set of reference readouts (206) using the different configurations, and generating a set of navigator images (210) with one navigator image (210) of the region of interest (142) for each configuration of the reference readouts (206), performing an examination phase comprising applying at least one scanning sequence (200), whereby at least one image (212) of the region of interest (142) is generated for each scanning sequence (200), determining motion of the subject of interest (120) by comparing at least one image (212) of the scanning sequence of the examination phase to the navigator image (210) having the same configuration as the compared image (212), performing motion correction of the at least one image (212) based on the determined motion of the subject of interest (120) of the at least one image (212), and providing an MR scan (214) of the region of interest (142) of the subject of interest (120) based on the images (212) after performing motion correction. The invention also provides a MR imaging system (110) adapted to perform the above method and a software package for upgrading a MR imaging system (110), whereby the software package contains instructions for controlling the MR imaging system (110) according to the above method.

SELECTIVE SAMPLING FOR ASSESSING STRUCTURAL SPATIAL FREQUENCIES WITH SPECIFIC CONTRAST MECHANISMS
20180329009 · 2018-11-15 ·

The disclosed embodiments provide a method for acquiring MR data at resolutions down to tens of microns for application in in vivo diagnosis and monitoring of pathology for which changes in fine tissue textures can be used as markers of disease onset and progression. Bone diseases, tumors, neurologic diseases, and diseases involving fibrotic growth and/or destruction are all target pathologies. Further the technique can be used in any biologic or physical system for which very high-resolution characterization of fine scale morphology is needed. The method provides rapid acquisition of signal at selected values in k-space, with multiple successive acquisitions at individual k-values taken on a time scale on the order of microseconds, within a defined tissue volume, and subsequent combination of the multiple measurements in such a way as to maximize SNR. The reduced acquisition volume, and acquisition of only signal values at select places in k-space, along selected directions, enables much higher in vivo resolution than is obtainable with current MRI techniques.

METHOD TO MEASURE TISSUE TEXTURE USING NMR SPECTROSCOPY TO IDENTIFY THE CHEMICAL SPECIES OF COMPONENT TEXTURAL ELEMENTS IN A TARGETED REGION OF TISSUE
20180313925 · 2018-11-01 ·

A method for identifying the chemical species of various textural elements in a targeted region of tissue wherein a volume of interest (VOI) is selectively excited and a k-encode gradient pulse is applied to induce phase wrap to create a spatial encode for a specific k-value and orientation. The specific k-value is selected based on anticipated texture within the VOI. Multiple sequential samples of the NMR RF signal encoded with the specific k-value are recorded as signal data. The Fourier Transform of the acquired signal data is then taken, wherein for each k-encode, the signal recorded is indicative of the spatial frequency power density at that point in k-space. Each peak in the NMR spectrum is then evaluated, whereby the relative contribution to the texture of tissue in the VOI at a k-value for each chemical species is determined.

ACCELERATED DYNAMIC MAGNETIC RESONANCE IMAGING USING LOW RANK MATRIX COMPLETION
20180306884 · 2018-10-25 ·

Accelerated dynamic magnetic resonance imaging (MRI) methods in which low-rank matrix completion is implemented as a pre-processing step to fill undersampled accelerated k-space while retaining both spatial and temporal resolution are described. The undersampled k-space data are acquired using multilevel sampling, in which both uniform undersampling and non-uniform undersampling are combined to achieve high temporal resolution while retaining spatial resolution.