The Ohio State University

Siemens Healthcare Gmbh

Siemens Medical Solutions USA, Inc.

Northwestern University

Cedars-Sinai Medical Center

Ning Jin

Orlando P Simonetti

Rizwan Ahmad

Peter Speier

Sven Zuehlsdorff

Adam Rich

Yu Ding

Marie-Pierre Jolly

Debiao Li

Xiaoming Bi

Dingxin Wang

Shivraman Giri

Christopher Glielmi

Michael Markl

Bruce S Spottiswoode

Lee C Potter

Kelvin Chow

Qi Liu

Jiang Pang

Yingmin Liu

Joshua Ash

In a method and magnetic resonance (MR) apparatus for pulse wave velocity (PWV) measurement along the aorta of a subject using MR imaging, a multislice cardio synchronized segmented cin&#xe9; MR data acquisition sequence is optimized in order to enhance inflow representation in the slice images, in order to make the multislice MR data acquisition sequence viable for clinical uses, so as to acquire intensity-based MR data from two transverse slices spaced from each other along the descending aorta. The respective intensities of relevant pixels in at least two respective slice images are analyzed in order to identify the arrival of a pulse wave in the respective slices by the onset of flow enhancement in the slices, represented by intensity changes in the pixels. From the onset of flow enhancement in the respective slice images, PWV is calculated. An electronic signal representing the calculated PWV is then provided from a computer.

Inflow-based pulse wave velocity profiling along the aorta using magnetic resonance imaging

A variable density Cartesian sampling method that allows retrospective adjustment of temporal resolution, providing added flexibility for real-time applications where optimal temporal resolution may not be known in advance. The methods provide for a computationally efficient sampling methods where a first step includes producing a uniformly random sampling pattern using a golden ratio on a grid, and the second step is applying a nonlinear stretching operation to create a variable density sampling pattern. Diagnostic quality images may be recovered at different temporal resolutions.

Cartesian sampling for dynamic magnetic resonance imaging (MRI)

Methods and systems for accelerated Phase-contrast magnetic resonance imaging (PC-MRI). The technique is based on Bayesian inference and provides for fast computation via an approximate message passing algorithm. The Bayesian formulation allows modeling and exploitation of the statistical relationships across space, time, and encodings in order to achieve reproducible estimation of flow from highly undersampled data.

Bayesian model for highly accelerated phase-contrast MRI

MRI techniques seek to simultaneously measure physiological parameters in multiple directions, requiring the application of multiple encoding magnetic field gradient waveforms. The use of multiple encoding waveforms degrades the temporal resolution of the measurement, or may distort the results depending on the methodology used to derive physiological parameters from the measured data. The disclosed Direct Inversion Reconstruction Method (DiR) provides distortion-free velocity images with high temporal resolution, without changing the method of acquiring the phase data. The disclosed method provides a more stable and accurate recovery of phase-based dynamic magnetic resonance signals with higher temporal resolution than current state-of-the-art methods.

Direct inversion for phase-based dynamic magnetic resonance measurements

Embodiments can provide a computer-implemented method for simultaneous multi-slice pulse wave velocity measurement, the method comprising simultaneously acquiring a plurality of multiple parallel images slices from a medical imaging device; shifting the plurality of image slices through modulation of the line-by-line phase patterns for each slice in the plurality of slices; deriving a plurality of image waveforms from the plurality of slices; measuring a distance between a plurality of imaging planes corresponding to the plurality of image slices; determining, for each of the image waveforms, a time-to marker; determining the temporal shift by calculating the difference between the time-to markers; and computing the pulse wave velocity by dividing the distance between the plurality of imaging planes by the temporal shift.

Simultaneous multi-slice phase pulse wave velocity measurement in a vessel

A computer-implemented method for performing spatiotemporal background phase correction for phase contrast velocity encoded magnetic resonance imaging includes performing a phase contrast magnetic resonance imaging scan of a region of interest within a patient to yield a complex image and calculating a plurality of filter cut-off frequencies based on physiological limits associated with the patient. A spatiotemporal filter is created based on the plurality of filter cut-off frequencies. This spatiotemporal filter is applied to the complex image to yield a low-pass filtered complex image. Then, complex division is performed using the complex image and the low-pass filtered complex image to yield a corrected image.

Spatiotemporal background phase correction for phase contrast velocity encoded MRI

A novel free-breathing myocardial T2* mapping combining multiple single-shot black-blood GRE-EPI images with automatic non-rigid motion correction. The present disclosure describes a method of accurate myocardial T2* measurements that is insensitive to respiratory motion, and is likely to reduce sensitivity to arrhythmia as well since each image is acquired in a single heart beat. The T2*-weighted GRE-EPI images are motion corrected using, e.g., automatic non-rigid motion correction to reduce mis-registration due to respiratory motion. A T2* map is calculated using the motion-corrected T2*-weighted images by fitting pixel intensities to a, e.g., two-parameter mono-exponential model.

Free-breathing myocardial T2* mapping using single-heartbeat, multi-shot, gradient echo-echo planar imaging (GRE-EPI) and automatic non-rigid motion correction

Systems and methods of correcting eddy current-induced background phase (EC-BP) in magnetic resonance imaging (PC-MRI) data. The method includes acquiring a slice of interest (SOI) at a first table position using a magnetic resonance imaging (MRI) scanner, the slice of interest having a predetermined imaging orientation and being acquired having predetermined gradient waveforms; acquiring at least one additional slice at a second table position using the MRI scanner, the at least one additional slice having a same imaging orientation as the slice of interest and being acquired using the same gradient waveforms as the slice of interest; determining time-averaged phase maps from the slice of interest and the at least one additional slice; determining a correction map from the time-averaged phase maps; and correcting a background phase (BP) of the slice of interest using the correction map.

Background phase correction for quantitative cardiovascular MRI

An MR imaging system uses multiple RF coils, for reducing image acquisition time, suitable for chemical exchange saturation transfer (CEST) imaging. Multiple RF (Radio Frequency) coils provide CEST imaging preparation in an anatomical volume by providing multiple interleaved RF pulses. The multiple interleaved RF pulses provide substantially increased RF pulse sequence duty cycle in the multiple RF coils relative to a duty cycle provided by a single coil of the multiple RF coils. The multiple RF coils subsequently provide RF excitation pulses in a reduced anatomical volume using k-space undersampling in an accelerated imaging method using the multiple RF coils and enable subsequent acquisition of associated RF echo data for deriving a CEST image.

MR parallel imaging system reducing imaging time

An imaging system automatically determines a cardiac timing parameter for acquiring a cardiac image in a heart phase. An interface receives data identifying a heart image orientation for image acquisition. A repository of data associates, for acquisition of an image in a particular heart phase, different image orientations with corresponding different data items identifying respective corresponding particular acquisition points within an individual heart cycle relative to a start point of the heart cycle. An acquisition timing processor determines from the repository of data, a particular acquisition point within an individual heart cycle relative to the start point of the heart cycle, in response to the received data identifying the heart image orientation and uses the determined particular acquisition point to provide a synchronization signal for triggering acquisition of an image at the particular heart phase.

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Powell, OH, United States of America

Ning Jin