Selective magnetic resonance imaging
AssigneeThe Regents of the University of California
InventorJiang Du
Life of this patent
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Abstract
Techniques and systems for magnetic resonance imaging are disclosed in this specification. In one aspect, imaging of tissues having short transverse relaxation times T2 is described including short echo time (TE) signal acquisition preceded by suppression of signal from the surrounding tissues having long transverse relaxation times T2, to increase the contrast and dynamic range of magnetic resonance (MR) images contributed by the tissues having short T2.
Claims24
A method performed by a magnetic resonance imaging system, the method comprising:
- preparing a magnetization of species within a sample;
- selectively modifying, for a select period of time, the prepared magnetization
- to suppress, at a given time, a component of the modified magnetization corresponding to two or more of the species having long transverse relaxation times, T2, and
- to identify, at the given time, a component of the modified magnetization corresponding to at least one of the species having a short transverse relaxation time, T2,
- wherein each short T2 is shorter than the select period of time, and the select period of time is shorter than each long T2;
- exciting, at the given time, the identified component of the modified magnetization corresponding to the at least one short T2 species;
- and
- detecting radio frequency (RF) emissions corresponding to relaxation of the excited magnetization corresponding to the at least one short T2 species.
A magnetic resonance imaging system comprising:
- a scanner comprising a magnet, gradient coils and a radio frequency (RF) transceiver to perform operations comprising:
- prepare a magnetization of species within a sample;
- selectively modify, for a select period of time, the prepared magnetization
- to suppress, at a given time, a component of the modified magnetization corresponding to two or more of the species having long transverse relaxation times, T2, and
- to identify, at the given time, a component of the modified magnetization corresponding to at least one species having a short transverse relaxation time, T2,
- wherein each short T2 is shorter than the select period of time, and the select period of time is shorter than each long T2;
- excite, at the given time, the identified component of the modified magnetization corresponding to the at least one short T2 species;
- and
- detect RF emissions corresponding to relaxation of the excited magnetization corresponding to the at least one short T2 species;
- and
- a data processor in communication with the scanner to perform operations comprising:
- receive the detected RF emissions;
- and
- convert the received RF emissions into an image contributed by the excited magnetization corresponding to the at least one short T2 species.
A method for nuclear magnetic resonance imaging (MRI), comprising:
- applying to a sample a first radio frequency (RF) pulse at a first resonance frequency to adiabatically invert nuclear spins having the first resonance frequency and a first transverse relaxation rate;
- applying to the sample a second RF pulse at a second resonance frequency to adiabatically invert nuclear spins having the second resonance frequency and a second transverse relaxation rate, wherein the nuclear spins having the first resonance frequency and the nuclear spins having the second resonance frequency simultaneously reach zero longitudinal magnetization states from inverted spin states due to longitudinal relaxation;
- and
- generating an image of at least part of the sample based on a magnetic resonance signal produced by a plurality of nuclear spins having one or more transverse relaxation rates that are faster than the first and second transverse relaxation rates.
Dependencies are inferred from the claim text.