Abstract: Systems and methods for designing and fabricating three-dimensional objects with precisely computed material compositions for use in enhancing electromagnetic fields for magnetic resonance imaging (“MRI”) are provided. As examples, the fabricated object can be designed to reduce magnetic field inhomogeneities in the main magnetic field of an MRI system, or to reduce inhomogeneities in a transmit radio frequency (“RF”) field (i.e., a B1 field). As examples, the object can be a shim; a housing or other part of an RF coil; a medical device, such as a surgical implant; or component used in a medical device, such as a housing for an implantable medical device.

Abstract: Systems and methods for performing diffusion-weighted multi-spectral imaging (“MS!”) with a magnetic resonance imaging (“MRI”) system are provided, Diffusion-weighted images can thus be acquired from a subject in which a metallic object, such as an implant or other device, is present. In general, a two-dimensional or three-dimensional diffusion-weighted PROPELLER acquisition is performed to acquire data from multiple different spectral bins. Images from the spectral bins are reconstructed and combined to form diffusion-weighted composite images. Non-CPMG phase-cycling and split-blade PROPELLER techniques are combined with PROPELLER MSI metal artifact mitigation principles to this end.

Abstract: Systems and methods for performing diffusion-weighted multi-spectral imaging (“MS!”) with a magnetic resonance imaging (“MRI”) system are provided, Diffusion-weighted images can thus be acquired from a subject in which a metallic object, such as an implant or other device, is present. In general, a two-dimensional or three-dimensional diffusion-weighted PROPELLER acquisition is performed to acquire data from multiple different spectral bins. Images from the spectral bins are reconstructed and combined to form diffusion-weighted composite images. Non-CPMG phase-cycling and split-blade PROPELLER techniques are combined with PROPELLER MSI metal artifact mitigation principles to this end.

Abstract: A method for highly accelerated projection imaging (“HAPI”) is provided. In this method, conventional linear gradients are used to obtain coil sensitivity-weighted projections of the object being imaged. Only a relatively small number of projections, such as sixteen or less, of the object are required to reconstruct a two-dimensional image of the object, unlike conventional projection imaging techniques. The relationship between the voxel values of the imaged object and the coil sensitivity-weighted projections is formulated as a linear system of equations and the reconstructed images are obtained by solving this matrix equation. This method advantageously allows higher acceleration rates compared to echo planar imaging (“EPI”) with SENSE or GRAPPA acceleration. Moreover, the method does not require any additional or specialized hardware because hardware in conventional MRI scanners is adequate to implement the method.

Abstract: A method for highly accelerated projection imaging (“HAPI”) is provided. In this method, conventional linear gradients are used to obtain coil sensitivity-weighted projections of the object being imaged. Only a relatively small number of projections, such as sixteen or less, of the object are required to reconstruct a two-dimensional image of the object, unlike conventional projection imaging techniques. The relationship between the voxel values of the imaged object and the coil sensitivity-weighted projections is formulated as a linear system of equations and the reconstructed images are obtained by solving this matrix equation. This method advantageously allows higher acceleration rates compared to echo planar imaging (“EPI”) with SENSE or GRAPPA acceleration. Moreover, the method does not require any additional or specialized hardware because hardware in conventional MRI scanners is adequate to implement the method.