Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Siemens Medical Solutions Usa, Inc.

Cedars-sinai Medical Center

Siemens Medical Systems, Inc.

Gerhard Laub

Yutaka Natsuaki

Xiaoming Bi

Peter Schmitt

Randall Kroeker

Debiao Li

Zhaoyang Fan

Vibhas Deshpande

David Grodzki

Berthold Kiefer

Matthias Fenchel

Orlando P Simonetti

Vibhas S Deshpande

Wilhelm Horger

Jianing Pang

Waqas Majeed

Michael Bock

Richard Hausmann

Christopher Nguyen

John William Grinstead

Qiang Zhang

Kevin Johnson

Jiamin Wang

Stefan O Schoenberg

Michael V Knopp

Wuyi Zhao

In the field of MRI, a model-based MRI image reconstruction technique is provided. The model-based reconstruction technique increases the performance of Time-of-Flight MRA. In a learning phase, a model is calculated from a sufficiently large set of data acquired at both low and high magnetic fields, using deep learning strategies. In a clinical phase, the model is applied to measured data generating high MR image quality.

MRI image reconstruction using machine learning

Embodiments can provide a computer-implemented method for free breathing three dimensional diffusion imaging, the method comprising initiating, via a k-space component processor, diffusion/T2 preparation, comprising generating diffusion contrast; and adjusting one or more of amplitude, duration, and polarity to set a first order moment; applying, via an image data processor, a stack of stars k-space ordering, comprising acquiring a radial/spiral view for all members of a plurality of partitions in a partition-encoding direction; increasing an azimuthal angle until a complete set of radial/spiral views are sampled; and applying diffusion gradients along each of three axis simultaneously; and calculating, via the image data processor, an apparent diffusion coefficient map.

Free-breathing 3D body diffusion imaging using motion-compensated diffusion preparation and motion robust readout

A method for performing 3D body imaging includes performing a 3D MRI acquisition of a patient to acquire k-space data and dividing the k-space data into k-space data bins. Each bin includes a portion of the k-space data corresponding to a distinct breathing phase. 3D image sets are reconstructed from the bins, with each 3D image set corresponding to a distinct k-space data bin. For each bin other than a selected reference bin, forward and inverse transforms are calculated between the 3D image set corresponding to the bin and the 3D image set corresponding to the reference bin. Then, a motion corrected and averaged image is generated for each bin by (a) aligning the 3D image set from each other bin to the 3D image set corresponding to the bin using the transforms, and (b) averaging the aligned 3D image sets to yield the motion corrected and averaged image.

Respiratory phase-resolved 3D body imaging using iterative motion correction and average

A system uses multiple RF coils in MR imaging and an RF (Radio Frequency) signal generator generates RF excitation pulses in anatomical regions of interest and enables subsequent acquisition of associated RF echo data. A magnetic field gradient generator generates anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition. The RF signal generator and the gradient generator substantially concurrently acquire first and second volumes of first and second different anatomical regions by providing, a first RF pulse having a first asymmetric shape followed by a successive second RF pulse substantially having the first asymmetric shape but reversed in time, to substantially reduce echo time (TE) differences between acquisition of the first and second volumes and a phase encoding magnetic field gradient prepares for acquisition of data representing the first and second volumes.

System for simultaneous dual-slab acquisition of MR images with asymmetric and time-reversed asymmetric, concatenated pulses

A method for acquiring an image volume using a magnetic resonance imaging device includes performing an acquisition process to acquire a first dataset corresponding to a first portion of an anatomical region of interest at a first slice resolution, wherein the first dataset comprises a first plurality of three-dimensional slabs or a first plurality of two-dimensional slice regions. Additionally, one or more additional acquisition processes is performed to acquire a second dataset corresponding to a second portion of the anatomical region of interest at a second slice resolution that is lower or higher than the first slice resolution, wherein the second dataset comprises a second plurality of three-dimensional slabs or a second plurality of two-dimensional slice regions. Once the datasets are acquired, a reconstruction process is applied to jointly reconstruct the first dataset and the second dataset as a single consistent volume.

Non-contrast MR angiography with variable slice resolution 3D time-of-flight

A method for using flexible triggered segmentation to optimize magnetic resonance imaging includes partitioning a k-space table into a plurality of k-space segments, each respective k-space segment comprising one or more phase-encoding steps from a plurality of slice-encoding lines. A cardiac cycle is monitored using an electrical signal tracking system and used to trigger acquisition of the plurality of k-space segments over a plurality of acquisition windows.

Methods, systems and apparatuses for using flexible triggered segmentation to optimize magnetic resonance imaging

A system includes applying, to patient tissue, a first imaging sequence comprising first balanced gradient pulse trains and RF pulses, where phases of successive RF pulses in the first imaging sequence differ by a first pulse phase increment, detecting first signals emitted from the patient tissue in response to the first imaging sequence, and to generate a first image based on the first signals, applying, to the patient tissue, a second imaging sequence comprising second balanced gradient pulse trains and RF pulses, where phases of successive RF pulses in the second imaging sequence differ by a second pulse phase increment different from the first pulse phase increment, detecting second signals emitted from the patient tissue in response to the second imaging sequence, and to generate a second image based on the second signals, applying motion-correction processing to the first image to generate a first motion-corrected image, applying motion-correction processing to the second image to generate a second motion-corrected image, and generating a composite image based on the first motion-corrected image and the second motion-corrected image.

Phase-cycled steady-state free precession imaging

A magnetic resonance method and system are provided for providing improved 3D imaging of blood vessels and the like, which provides suppression of both blood and fat signals and is insensitive to subject motion, thereby facilitating improved visualization of vessel walls. The image data pulse sequence includes a plurality of pulse series, where each series includes a dark-blood sequence, a fat-suppression sequence, and a data readout sequence. Each data readout sequence samples a particular radial direction within each partition (Kz value) that passes through the Kz axis, and different radial orientations are sampled in subsequent series to provide a stack-of-stars sampling scheme.

System and method for motion-robust 3D magnetic resonance imaging of vessel walls

A system orders acquisition of frequency domain components representing MR image data for storage in a storage array (e.g., k-space). A storage array of individual data elements stores corresponding individual frequency components comprising an MR dataset. The array of individual data elements has a designated center and individual data elements individually have a radius to the designated center. A magnetic field generator generates a magnetic field for use in acquiring multiple individual frequency components corresponding to individual data elements in the storage array. The individual frequency components are successively acquired in an order in which radius of respective corresponding individual data elements increases and decreases as the multiple individual frequency components are sequentially acquired during acquisition of an MR dataset representing an MR image. A storage processor stores individual frequency components acquired using the magnetic field in corresponding individual data elements in the array.

System for ordering frequency domain components representing MR image data

An MR imaging system without the use of a contrast agent, in a first repetition time interval, generates a non-selective magnetization preparation pulse for magnetizing an anatomical volume encompassing blood flowing into a selected slab within the volume for blood signal suppression, generates RF excitation pulses and acquires a first MR imaging dataset of the selected slab within the volume with a suppressed blood signal. The system in a second repetition time interval succeeding the first repetition time interval, generates a selected slab magnetization preparation pulse for magnetizing the selected slab, generates RF excitation pulses and acquires a second MR imaging dataset of the selected slab within the volume. An image data processor substantially subtracts imaging data of the first MR imaging dataset from the second MR imaging dataset to provide an image enhancing a vessel structure in the selected slab and also substantially averages imaging data to provide an MR anatomical image.

System for concurrent acquisition of MR anatomical brain images and MR angiograms without contrast-injection

System for ordering acquisition of frequency domain components representing MR image data

In a method and system for displaying a medical image, a user defines three points in an anatomy of interest at different locations. A plane is then automatically generated from the three points.

Multi-planar reformating using a three-point tool

In a method for operating a magnetic resonance imaging system to generate a magnetic resonance data file, raw magnetic resonance data are acquired, and k-space is established in a computerized storage medium, with k-space being divided into a contiguous central region and a contiguous region surrounding the central region. In a computerized procedure, the raw data are entered into k-space at a constant sampling rate for both of the central and peripheral regions, while sampling the central region with a first density of sampling points, and sampling the peripheral region at a second density of sampling points that is less than the first sampling density. The set of data points thereby representing sampled k-space is made available in a data file as an output from the computerized procedure, in a form allowing an image to be reconstructed from the contents of the data file.

Method and apparatus for generating a magnetic resonance data file

In a magnetic resonance imaging apparatus and a method for operating the apparatus, a trueFISP sequence is used, but is modified to employ non-selective, rectangular radio frequency pulses. The use of non-selective excitation pulses reduces the sensitivity to off-resonance and allows excitation to be achieved in a shorter time compared to selective excitation, thereby shortening the time between echoes and minimizing slice profile issues.

Magnetic resonance imaging method and apparatus with non-selective excitation of the examination subject

Systems and techniques for acquiring a medical image of a region of interest are described. A plurality of electromagnetic excitation pulses are applied to the region of interest according to predetermined parameters, and a predetermined delay period is introduced after which the longitudinal magnetization of a first species generated within the region of interest reaches zero and a longitudinal magnetization of a second species generated within the region of interest is in steady-state.

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San Mateo, CA, United States of America

Gerhard Laub