US 2015/0316634 A1Published application

Nuclear Magnetic Resonance (NMR) Fingerprinting With Parallel Transmission

AssigneeCase Western Reserve University

InventorMark Griswold

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Abstract

Apparatus, methods, and other embodiments associated with NMR fingerprinting with parallel transmission are described. One example apparatus includes individually controllable radio frequency (RF) transmission (TX) coils configured to apply varying NMR fingerprinting RF excitations to a sample. The NMR apparatus may apply excitations in parallel. An individual excitation causes different resonant species to produce different signal evolutions. The apparatus includes a parallel transmission logic that causes one of the coils to apply a first excitation to the sample and that causes a different coil to apply a second, different excitation to the sample. The excitations are configured to produce a spatial inhomogeneity between a first region in the sample and a second region in the sample that allows a resonant species to produce a first signal evolution in the first region and to produce a second signal evolution in the second region to facilitate de-correlating the signal evolutions.

Claims20

Dependent claims

A computer-readable medium storing computer-executable instructions that when executed perform a method for controlling a nuclear magnetic resonance (NMR) apparatus configured with two or more individually controllable transmit (TX) coils, the method comprising:

controlling the NMR apparatus to apply to a sample a first NMR fingerprinting radio frequency (RF) excitation from a first of the two or more TX coils;
controlling the NMR apparatus to apply to the sample a second, different NMR fingerprinting RF excitation from a second of the two or more TX coils,
where the first NMR RF excitation and the second NMR RF excitation vary in flip angle in an amount sufficient to produce an inhomogeneous flip angle distribution in the sample;
controlling the NMR apparatus to simultaneously acquire individual NMR signal evolutions produced in response to applying the first NMR fingerprinting RF excitation and the second NMR fingerprinting RF excitation;
controlling the NMR apparatus to produce a characterization of at least one of the resonant species as a function of comparing the acquired individual NMR signals to one or more known signal evolutions,
where characterizing a resonant species comprises simultaneously identifying two or more parameters selected from, T1 relaxation associated with the resonant species, T2 relaxation associated with the resonant species, off-resonance relaxation associated with the resonant species, and diffusion weighted relaxation associated with the resonant species,
producing a parameter map or image based on the characterization of the at least one of the resonant species, and
providing the parameter map or the image.

5 more elements

A nuclear magnetic resonance (NMR) apparatus, comprising:

a plurality of individually controllable radio frequency (RF) transmission (TX) coils configured to apply NMR fingerprinting RF excitations to a sample, where an NMR fingerprinting RF excitation is characterized, at least in part, by a first flip angle for a first gradient that is controllable by the NMR apparatus, by a second flip angle for a second gradient that is controllable by the NMR apparatus, and by a third flip angle for a third gradient that is controllable by the NMR apparatus;
a parallel transmission logic configured to control members of the plurality of individually controllable RF TX coils to apply a series of different NMR fingerprinting RF excitations to the sample,
where consecutive members of the series are applied from different members of the plurality of individually controllable RF TX coils, and
where consecutive members of the series have different flip angles that are sufficient to produce a spatial inhomogeneity associated with a flip angle distribution,
an NMR logic configured to repetitively and variably sample a (k, t, E) space associated with the sample to acquire a set of NMR signals, where members of the set of NMR signals are associated with different points in the (k, t, E) space, where t is time and E includes at least T1, T2, and one other relaxation parameter, T1 being spin-lattice relaxation, and T2 being spin-spin relaxation, and where one or more of, t, and E, vary non-linearly;
a signal logic configured to produce an NMR signal evolution from the set of NMR signals,
a matching logic configured to compare the produced NMR signal evolution to a known NMR signal evolution, and
a characterization logic configured:
to characterize a resonant species in the object based, at least in part, on comparing the produced NMR signal evolution to the known NMR signal evolution,
to provide image pixel data suitable for producing a diagnostic image, where the image pixel data is identified from correlations between the produced NMR signal evolution and the known NMR signal evolution and between the known signal evolution and the image pixel data, and
to provide relaxation parameter data identified from correlations between the produced NMR signal evolution and the known NMR signal evolution and between the known signal evolution and the relaxation parameter data.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/753,945Filed 29 Jun 2015
Priority: 12 Apr 2012
Published: 5 Nov 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G01R 33/5612
Parallel magnetic resonance imaging, e.g. sensitivity encoding [SENSE], simultaneous acquisition of spatial harmonics [SMASH], unaliasing by…:…
G01R 33/34
Excitation or detection systems, e.g. using radio frequency signals: constructional details, e.g. resonators , specially adapted to MR
G01R 33/385
Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field: using gradient magnetic field coils
G01R 33/4828
NMR imaging systems: resolving the MR signals of different chemical species, e.g. water-fat imaging

Family

Application13/445,122Continuation · filed 12 Apr 2012
Application14/753,945Continuation
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From the US filing history. Foreign family members aren’t listed.