Field-invariant quantitative magnetic-resonance signatures

A non-transitory computer-readable storage medium for use in conjunction with a magnetic-resonance (MR) scanner, the computer-readable storage medium storing a program module, wherein, when executed by the MR scanner, the program module causes the MR scanner to determine an MR signature of a biological sample by performing one or more operations comprising:

• providing, to the MR scanner, scanning instructions to capture MR signals of one or more types of nuclei in the biological sample, wherein the MR signals are associated with voxels at three-dimensional (3D) positions in the biological sample, and wherein the scanning instructions include at least a magnetic-field strength and a pulse sequence to be applied to the biological sample;
• and
• receiving, from the MR scanner, the MR signals;
• determining an MR model of the voxels in the biological sample based on the MR signals and the scanning instructions, wherein the MR model is based at least in part on model parameters, a simulation technique and predetermined characteristics of the MR scanner, including magnetic-field inhomogeneity and noise characteristics, and wherein determining the MR model involves:
• generating simulated MR signals for the biological sample based on the MR model and the scanning instructions and
• comparing the simulated MR signals and the MR signals to determine a difference vector;
• iteratively modifying the scanning instructions based on the difference vector and repeating the providing, the receiving and the determining until a convergence criterion is achieved, wherein the modified scanning instructions include changes to at least one of the magnetic-field strength and the pulse sequence;
• and
• storing, in the memory, an identifier of the biological sample and an invariant MR signature of the biological sample that corresponds to the MR model after the convergence criterion is achieved and that describes a dynamic MR response of the voxels in the biological sample at an arbitrary magnetic-field strength and with predetermined characteristics of an arbitrary MR scanner.

A method for determining a magnetic-resonance (MR) signature of a biological sample using an MR scanner, the method comprising:

• by a computer:
• providing, to the MR scanner, scanning instructions to capture MR signals of one or more types of nuclei in the biological sample, wherein the MR signals are associated with voxels at three-dimensional (3D) positions in the biological sample, and wherein the scanning instructions include at least a magnetic-field strength and a pulse sequence to be applied to the biological sample;
• and
• receiving, from the MR scanner, the MR signals;
• determining an MR model of the voxels in the biological sample based on the MR signals and the scanning instructions, wherein the MR model is based at least in part on model parameters, a simulation technique and predetermined characteristics of the MR scanner, including magnetic-field inhomogeneity and noise characteristics, and wherein determining the MR model involves:
• generating simulated MR signals for the biological sample based on the MR model and the scanning instructions and
• comparing the simulated MR signals and the MR signals to determine a difference vector;
• iteratively modifying the scanning instructions based on the difference vector and repeating the providing, the receiving and the determining until a convergence criterion is achieved, wherein the modified scanning instructions include changes to at least one of the magnetic-field strength and the pulse sequence;
• and
• storing, in the memory, an identifier of the biological sample and an invariant MR signature of the biological sample that corresponds to the MR model after the convergence criterion is achieved and that describes a dynamic MR response of the voxels in the biological sample at an arbitrary magnetic-field strength and with predetermined characteristics of an arbitrary MR scanner.