Magnetic resonance T2 preparatory pulses for magnetic field inhomogeneity robustness and contrast optimization
AssigneeGeneral Electric Company
InventorsFlorian Wiesinger, Martin Andreas Janich, Ana Beatriz Solana Sanchez, Nicolas Hehn
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Abstract
Methods and systems to obtain and apply T2 preparatory radiofrequency (RF) pulse sequences for magnetic resonance imaging (MRI) are provided. The iterative methods may employ propagation of the magnetization state of the object being imaged and a comparison with a target magnetization state. The methods disclosed may be used to obtain MRI pulse sequences that may optimize T2 relaxation contrast. The produced RF pulse sequences may be robust to effects from inhomogeneity of the magnetic fields or other environmental or physiological perturbations.
Claims20
A magnetic resonance imaging method employing a preparatory radiofrequency (RF) pulse sequence that enhances a target T2 relaxation contrast, wherein the preparatory RF pulse sequence is obtained using a method comprising:
- simulating a magnetization evolution of a gyromagnetic material based on a candidate RF pulse sequence, a parameter of the gyromagnetic material, and magnetic fields generated within the gyromagnetic material;
- calculating a quality of the candidate RF pulse sequence based on the magnetization evolution of the gyromagnetic material and the target T2 relaxation contrast;
- updating the candidate RF pulse sequence based on the magnetization evolution of the gyromagnetic material and the target T2 relaxation contrast and in response to a comparison between the quality of the candidate RF pulse sequence and a quality threshold, wherein updating the candidate RF pulse sequence improves the quality of the candidate RF pulse sequence relative to the quality threshold;
- and
- providing the candidate RF pulse sequence as the preparatory RF pulse sequence in response to the comparison between the quality of the candidate RF pulse sequence and the quality threshold.
A magnetic resonance imaging system comprising a pulse calculation module configured to perform a method to generate a T2 preparatory radiofrequency (RF) pulse sequence that enhances a target T2 relaxation contrast, the method comprising:
- simulating a magnetization evolution of a gyromagnetic material based at least on a candidate RF pulse sequence and a magnetic field generated within the gyromagnetic material;
- calculating a quality of the candidate RF pulse sequence based on a comparison between the magnetization evolution of the gyromagnetic material and a target magnetization evolution of the gyromagnetic material calculated from the target T2 relaxation contrast;
- and
- updating the candidate RF pulse sequence based in part on the comparison between the magnetization evolution of the gyromagnetic material and the target magnetization evolution of the gyromagnetic material and in response to a comparison between the quality of the candidate RF pulse sequence and a quality threshold.
A preparation module configured for use with a magnetic resonance imaging system and configured to perform a process to generate a radiofrequency (RF) pulse sequence that enhances a target T2 relaxation contrast, the method comprising:
- simulating a magnetization evolution of a gyromagnetic material based at least on a candidate RF pulse sequence, a material parameter of the gyromagnetic material, and a magnetic field generated within the gyromagnetic material;
- calculating a quality of the candidate RF pulse sequence based on a comparison between the magnetization evolution and a target magnetization evolution of the gyromagnetic material calculated from the target T2 relaxation contrast;
- and
- updating the candidate RF pulse sequence based in part on the comparison between the magnetization evolution and the target magnetization evolution and in response to determining that the quality of the candidate RF pulse sequence is below a quality threshold.
Dependencies are inferred from the claim text.