Case Western Reserve University

Other

Siemens Aktiengesellschaft

The General Hospital Corporation

University College Cardiff Consultants Limited

Dan Ma

Mark A Griswold

Vikas Gulani

Yun Jiang

Nicole Seiberlich

Katherine Wright

Jeffrey L Sunshine

Kecheng Liu

Tiejun Zhao

Debra McGivney

Anagha Deshmane

Chaitra Badve

Lawrence Leroy Wald

Kawin Setsompop

Susann Brady-Kalnay

Chris Flask

Luis Hernandez-Garcia

Alice Yang

Rasim Boyacioglu

Kenneth Loparo

Huihui Ye

Lan Lu

Ying Gao

Kechung Liu

Renate Jerecic

Lars Mueller

Derek Jones

Nahal Geshnizjani

Maryam Afzali

A method for determining an undersampling error for a magnetic resonance fingerprinting (MRF) pulse sequence includes retrieving a plurality of sets of spatial response functions. Each set of spatial response functions is associated with a tissue type in a reference image and is based on a tissue mask of the reference image for each tissue type. A signal evolution for each tissue type may be generated based on, for example, the MRF pulse sequence, An undersampled image may be generated for each tissue type using the set of spatial response functions and the signal evolutions for the tissue type. At least one quantitative parameter may be determined by comparing an undersampled image series created from the undersampled images to an MRF dictionary. An undersampling error for the MRF pulse sequence may be generated by comparing a quantitative map (or maps) for the quantitative parameter (or parameters) and the reference image.

System and method for determining undersampling errors for a magnetic resonance fingerprinting pulse sequence

A method for multi-dimensional, relaxation-diffusion magnetic resonance fingerprinting (MRF) includes performing, using a magnetic resonance imaging (MRI) system, a pulse sequence that integrates free-waveform b-tensor diffusion encoding into a magnet resonance fingerprinting pulse sequence to perform a multi-dimensional, relaxation-diffusion encoding while acquiring MRF signal evolutions, processing, using a processor, the acquired MRF signal evolutions to determine at least one relaxation parameter and at least one diffusivity parameter, and generating, using the processor, a report including at least one of the at least one relaxation parameter and the at least diffusivity parameter.

System and method for magnetic resonance fingerprinting with relaxation and diffusion data acquisition

Apparatus, methods, and other embodiments associated with NMR fingerprinting are described. One example NMR apparatus includes an NMR logic that repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. Sampling is performed in response to a diffusion-weighted double-echo pulse sequence. Sampling acquires transient-state signals of the double-echo sequence. The NMR apparatus may also include a signal logic that produces an NMR signal evolution from the NMR signals, and a characterization logic that characterizes a resonant species in the object as a result of comparing acquired signals to reference signals.

Diffusion-weighted double-echo magnetic resonance fingerprinting (MRF)

Example apparatus and methods improve magnetic resonance fingerprinting (MRF) by performing MRF with optimized spatial encoding, parallel imaging, and utilization of field inhomogeneities. Multi-echo radial trajectories and spiral trajectories may acquire data according to sampling schemes based on models of charge distribution on a sphere. Non-uniform sampling schemes may account for differences in detector coil performance. Field inhomogeneities provide spatial information that enhances the spatial separation of an MRF signal and facilitates unaliasing pixels. The field inhomogeneity may be manipulated. An MRF pulse sequence may include frequency selective RF pulses that are determined by the field inhomogeneities. Inhomogeneities combined with selective RF pulses result in higher acquisition efficiency.

Magnetic resonance fingerprinting (MRF) with efficient acquisition schemes

A method for magnetic resonance fingerprinting (MRF) with reduced acoustic noise includes accessing a MRF dictionary using a magnetic resonance imaging (MRI) system, acquiring MRF data using the MRI system and a pulse sequence comprising a plurality of arbitrary gradient waveforms for each gradient axis and random repetition times to control acoustic noise, comparing the MRF data to the MRF dictionary to identify at least one parameter of the MRF data and generating a report indicating the at least one parameter of the MRF data.

System and method for magnetic resonance fingerprinting with reduced acoustic noise

Apparatus, methods, and other embodiments associated with NMR fingerprinting are described. One example NMR apparatus includes an NMR logic configured to repetitively and variably sample a (k, t, E) space associated with an object to acquire a set of NMR signals. Members of the set of NMR signals are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The varying parameters may include flip angle, echo time, RF amplitude, and other parameters. The NMR apparatus may also include a signal logic configured to produce an NMR signal evolution from the NMR signals, and a characterization logic configured to characterize a resonant species in the object as a result of comparing acquired signals to reference signals.

Nuclear magnetic resonance (NMR) fingerprinting

Example apparatus and methods employ an artificial neural network (ANN) to automatically design magnetic resonance (MR) pulse sequences. The ANN is trained using transverse magnetization signal evolutions having arbitrary initial magnetizations. The trained up ANN may then produce an array of signal evolutions associated with a pulse sequence having user selectable pulse sequence parameters that vary in degrees of freedom associated with magnetic resonance fingerprinting (MRF). Efficient and accurate approaches are provided for predicting user controllable MR pulse sequence settings including, but not limited to, acquisition period and flip angle (FA). The acquisition period and FA may be different in different sequence blocks in the pulse sequence produced by the ANN. Predicting user controllable MR pulse sequence settings for both conventional MR and MRF facilitates achieving desired signal characteristics from a signal evolution produced in response to an automatically generated pulse sequence.

Magnetic resonance fingerprinting (MRF) serial artificial neural network (ANN) sequence design

Apparatus, methods, and other embodiments associated with NMR fingerprinting are described. One example NMR apparatus includes an NMR logic that repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The NMR apparatus may also include a signal logic that produces an NMR signal evolution from the NMR signals, and a characterization logic that characterizes a resonant species in the object as a result of comparing acquired signals to reference signals. The NMR signal evolution may be assigned to a cluster based on the characterization of the resonant species. Cluster overlay maps may be produced simultaneously based, at least in part, on the clustering. The clusters may be associated with different tissue types.

Nuclear magnetic resonance (NMR) fingerprinting tissue classification and image segmentation

Apparatus, methods, and other embodiments associated with NMR fingerprinting are described. One example NMR apparatus includes an NMR logic configured to repetitively and variably sample a (k, t, E) space associated with an object to acquire a set of NMR signals. Members of the set of NMR signals are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The varying parameters may include flip angle, echo time, RF amplitude, and other parameters. The NMR apparatus may also include a signal logic configured to produce an NMR signal evolution from the NMR signals, a matching logic configured to compare a signal evolution to a known, simulated or predicted signal evolution, and a characterization logic configured to characterize a resonant species in the object as a result of the signal evolution comparisons.

Embodiments associated with combined magnetic resonance angiography and perfusion (MRAP) and nuclear magnetic resonance (NMR) fingerprinting are described. One example apparatus repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The apparatus includes a signal logic that produces an NMR signal evolution from the NMR signals and a characterization logic that characterizes a resonant species in the object as a result of comparing acquired signals to reference signals. The apparatus includes an MRAP logic that simultaneously performs MR angiography and produces quantitative perfusion maps. A multi-factor MR bio-imaging panel is produced from a combination of the data provided by the MRAP and NMR fingerprinting. Diagnoses may be made from the multi-factor MR bio-imaging panel.

Simultaneous magnetic resonance angiography and perfusion with nuclear magnetic resonance fingerprinting

Example embodiments associated with NMR fingerprinting are described. One example NMR apparatus includes an NMR logic that repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. Sampling is performed in response to a fast imaging with steady state free precession (MRF-FISP) pulse sequence having an unbalanced gradient that dephases transverse magnetization. The NMR apparatus may also include a signal logic that produces an NMR signal evolution from the NMR signals, and a characterization logic that characterizes a resonant species in the object as a result of comparing acquired signals to reference signals. The unbalanced gradient in the MRF-FISP pulse sequence reduces sensitivity to Bin homogeneity.

Magnetic resonance fingerprinting with steady state precession (MRF-FISP)

A system and method is provided for operating a high-field magnetic resonance (MR) system includes performing a series of data acquisition modules without respiratory gating. Each data acquisition module is formed of a steady-state free precession pulse sequence. Performing the series of data acquisition modules includes varying at least one of an amplitude of an excitation pulse or a repetition time of the steady-state free precession pulse sequence between adjacent data acquisition modules in the series of data acquisition modules to acquire a series of MR data with random or pseudo-random imaging acquisition parameters. The series of MR data is compared to a dictionary of signal evolution profiles to determine a match between the series of MR data with at least one signal evolution profile in the dictionary indicating at least one quantitative parameter in the subject.

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Cleveland Heights, OH, United States of America

Dan Ma