Wisconsin Alumni Research Foundation

Nathan Samuel Artz

Scott Brian Reeder

Matthew Robert Smith

Samir Sharma

Curtis N Wiens

A system and method for accelerated magnetic resonance imaging (MRI) includes controlling an RF system of an MRI system to acquire coil calibration data from a subject including a material causing inhomogeneities in a static magnetic field of the MRI system when arranged in the bore of the MRI system. After acquiring the coil calibration data, the RF system is controlled to acquire imaging data from the subject at multiple different resonance frequency offsets. The spectral bin images relate specific resonance frequencies to distinct spatial locations in the static magnetic field of the MRI system. An image of the subject is reconstructed from the imaging data using coil calibration data and the spectral bin data to provide spatial encoding of the image.

System and method for externally calibrated parallel imaging in the presence of an inhomogeneous magnetic field

An object-based approach is used to initialize the magnetic field inhomogeneity estimation for chemical species separation, such as water-fat separation, and other imaging applications. For example, a susceptibility distribution in the subject being imaged is estimated from images reconstructed from single-echo or multi-echo k-space data and used to initialize the magnetic field inhomogeneity estimation. This approach can be applied to any complex-based chemical shift encoded chemical species separation technique and to other imaging applications, such as susceptibility-weighted imaging and quantitative susceptibility mapping. The field map can also be used to correct for image distortions and to generate magnetic field shimming values.

System and method for object-based initialization of magnetic field inhomogeneity in magnetic resonance imaging

Systems and methods for simultaneously acquiring three-dimensional data from multiple different frequency bins with a magnetic resonance imaging ('MRI') system, and without frequency-encoding gradients, are provided. A multiband radio frequency ('RF') pulse is used to excite spins associated with multiple different resonance frequency offsets, and a fully phase-encoded acquisition is used to acquire data, which may be spectrally-resolved data, from magnetic resonance signals formed in response to the multiband RF pulse.

System and method for fully phase-encoded magnetic resonance imaging using multiband radio frequency excitation

A system and method for acquiring spectrally-resolved three-dimensional data with a magnetic resonance imaging ('MRI') system without frequency-encoding gradients are provided. An MRI system is directed to produce a radio frequency ('RF') pulse that rotates net magnetization about an axis, after which a first phase-encoding gradient is established along a first direction, a second phase-encoding gradient is established along a second direction that is orthogonal to the first direction, and a third phase-encoding gradient is established along a third direction that is orthogonal to the first and second directions. Spectrally-resolved data are acquired at a point in k-space that is defined by the first, second, and third phase-encoding gradients, and is acquired by sampling a magnetic resonance signal at a plurality of time points during a period of time in which no magnetic field gradients are established by the MRI system.

System and method for spectrally-resolved three-dimensional magnetic resonance imaging without frequency-encoding gradients

A system and method for accelerated magnetic resonance imaging (MRI) using spectral sensitivity information are provided. The MRI system is used to acquire k-space data from a subject that when positioned in the main magnetic field of the MRI system causes inhomogeneities in the main magnetic field. Spectral sensitivity information is derived from the acquired k-space data. In general, the spectral sensitivity information relates specific resonance frequencies to distinct spatial locations in the main magnetic field of the MRI system. One or more images of the subject may be reconstructed from the acquired k-space data using the produced spectral sensitivity information to spatially encode the acquired k-space data. By using the spectral sensitivity information to provide spatial-encoding, the data acquisition can be accelerated, for example, by undersampling k-space. In addition, using the provided system and method, clinically viable images can be obtained in the presence of severe off-resonance.

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Sun Prairie, WI, United States of America

Nathan Samuel Artz