Multiplicative increase in mri data acquisition with multi-band rf excitation pulses in a simultaneous image refocusing pulse sequence
OwnerDavid FEINBERG, Kamil Ugurbilinventors
Life of this patent
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Abstract
Disclosed are methods and systems for carrying out super-multiplexed magnetic resonance imaging that entwines techniques previously used individually and independently of each other in Simultaneous Echo (of Imaging) Refocusing (SER or SIR) and Multi-Band (MB) excitation, in a single pulse sequence that provides a multiplication rather than summation of desirable effects while suppressing undesirable effects of each of the techniques that previously were used independently.
Claims20
A magnetic resonance imaging (MRI) method comprising:
- applying, to a subject in an MRI scanner, a set of S radiofrequency (RF) excitation pulses in a time sequence, each pulse S being a multi-band pulse that simultaneously excites M respective slices in each of M volumes of the subject, thereby causing the subject to emit, in a time sequence, S MRI signals, where S≧2 and M≧2;
- refocusing the MRI signals to thereby generate a train of N sets of S MRI signals each, where N≧2;
- acquiring the MRI signals with at least one set of RF receiver coils having spatial sensitivity characteristics;
- computer-processing the MRI signals acquired with said RF receiver coils to produce magnetic resonance image data for S×M slices of the subject;
- and
- further computer-processing at least some of said magnetic resonance image data to produce magnetic resonance images of at least some of said S×M slices of the subject.
A magnetic resonance (MRI) scanner system comprising:
- an MRI scanner having a source of a steady magnetic field Bo, sources of gradient magnetic fields acting on an imaging volume of the MRI scanner for containing a subject, and an RF system selectively applying RF excitation pulses to the imaging space and receiving MRI signals from the imaging space and subject therein in response thereto;
- a control and signal processing computer system coupled with said RF system and said sources of gradient fields, said computer system being configured to cause said MRI scanner to:
- apply to said imaging space and subject therein, through said RF system, a set of S radiofrequency (RF) excitation pulses in a time sequence, each pulse S being a multi-band pulse that simultaneously excites M respective slices in each of M volumes of the imaging space and subject therein, thereby causing the imaging space and subject to emit, in a time sequence, S MRI signals, where S≧2 and M≧2;
- refocus the MRI signals, through said sources of gradient pulses, to thereby generate a train of N sets of S MRI signals each, where N≧2;
- acquire the MRI signals through said RF system with spatial sensitivities encoded in the acquired MRI signals;
- and
- computer-process the MRI signals acquired through said RF system to produce magnetic resonance image data for more than S+M but no more than S×M slices of the imaging space and subject.
A computer program product comprising computer-readable programs stored on a computer-readable medium in a non-transitory form which, when loaded on and executed with an MRI scanner system comprising an MRI scanner having a source of a steady magnetic field Bo, sources of gradient magnetic fields acting on a subject in an imaging volume of the MRI scanner, and an RF system selectively applying RF excitation pulses to the subject and receiving MRI signals from the subject in response thereto, causes the MRI scanner system to carry out the steps of:
- applying to said subject, through said RF system, a set of S radiofrequency (RF) excitation pulses in a time sequence, each pulse S being a multi-band pulse that simultaneously excites M respective slices in each of M volumes of the subject, thereby causing the subject to emit, in a time sequence, S MRI signals, where S≧2 and M≧2;
- refocusing the signals, through said sources of gradient pulses, to thereby generate a train of N sets of S MRI signals each, where N≧2;
- acquiring the MRI signals through said RF system with spatial sensitivities encoded in the acquired MRI signals;
- and
- computer-processing the MRI signals acquired through said RF system to produce magnetic resonance image data for more than S+M but no more than S×M slices of the subject.
Dependencies are inferred from the claim text.