Wisconsin Alumni Research Foundation

Sean Fain

James Hartman Holmes

Thomas M Grist

Krishna Nagaraj Kurpad

Matthew G Erickson

Rafael L O'Halloran

Walter Francis Block

Kevin Michael Johnson

Eric Peterson

Xu Zhai

Andrew Hahn

Krishna N Kuprad

Jeffrey Kammerman

Jeremy W Gordon

A system and method is provided to acquire images of a subject having received a tissue soluble hyperpolarized gas into the airways. The method includes performing a pulse sequence including (i) for each effective repetition time (TReff), acquiring at least one gas-phase dataset and at least one dissolved-phase dataset, wherein a gas-phase echo time (TEGas) of the at least one gas-phase dataset and a dissolved-phase echo time (TEDissolved) of the at least one dissolved-phase dataset are selected to isolate gas-phase contamination of the dissolved-phase dataset from dissolved-phase components in the dissolved-phase dataset. The method also includes (ii) estimating gas-phase contamination of the dissolved-phase dataset using the gas-phase dataset and a scaling factor (&#x3c3;), (iii) producing a corrected dissolved-phase dataset by reducing the gas-phase contamination of the dissolved-phase dataset using the gas-phase contamination estimated in step (ii), and reconstructing an image from the corrected dissolved-phase dataset and the gas-phase dataset.

System and method for control of hyperpolarized gas-phase contamination in spectroscopic magnetic resonance imaging

A local breast coil is designed to be tightly coupled to the natural shape of the pendant breast to provide high SNR for diagnostic MR imaging applications, while still providing access for interventional procedures through openings in the coil. In accordance with one configuration, the coil has a symmetrical design, such that the coil can be rotated about the breast to position an opening in the coil proximate to a desired portion of the breast without incurring registration or other alignment or artifact errors due to inhomogeneous Bexcitation. Furthermore, the coil is designed to facilitate medial and lateral imaging of the breast. The coil is combined with a patient support system that facilitates rotation of the coil and interchangeability of the coil to match the configuration of the coil to the position of the breast being imaged.

Local MRI breast coil and method of use

A system and method for simultaneously generating spectral images and spatial images of a subject using a magnetic resonance imaging (MRI) system includes acquiring MR image data using a k-space sampling trajectory. The k-space sampling trajectory is designed to spatially oversample to elicit phase differences between oversampled points. The MR image data is jointly reconstructed into spatial and spectral images by resolving spatial information from spatial encoding associated with each of the oversampled points and resolving spectral information from the phase differences between the oversampled points.

System and method for joint reconstruction of spatial and spectral imaging data

An image reconstruction method includes reconstructing an initial composite image of a subject using a conventional reconstruction method. The initial composite image employs the best information available regarding the subject of the scan and this information is used to constrain the reconstruction of a highly undersampled or low SNR image frames. This highly constrained image reconstruction is repeated a plurality of iterations with the reconstructed image frame for one iteration being used as the composite image for the next iteration. The reconstructed image frame rapidly converges to a final image frame.

Iterative highly constrained image reconstruction method

A method for measuring the apparent transverse relaxation time ('T*') and apparent diffusion coefficient ('ADC') of a hyperpolarized gas in a single breath-hold and consequently, with a single dose of the hyperpolarized gas contrast agent, is provided. The method employs a multiple-echo projection acquisition based pulse sequence. Individual images are reconstructed from data acquired during each of the individual echo times. Subsequently, T*and ADC are calculated using these reconstructed images. Furthermore, the method produces images indicative of ADC that have isotropic resolution, allowing for more reliable image registration. The inter-echo spacing and diffusion weighting b-value are varied during the pulse sequence employed when practicing the present invention; thus, a significant separation between the effects of diffusion and T*decay on the detected MR signals is possible. This separation allows for reliable measurements of these two parameters from a single echo-train.

Method for simultaneously measuring T2* and diffusion with magnetic resonance imaging

Diagnostic MR images of the lung are segmented to distinguish the airway tree from lung parenchyma. Diffusion weighted images of the lungs are acquired using hyperpolarized gas MRI and a segmentation image is produced from the apparent diffusion coefficient (ADC) image calculated from the diffusion weighted images. Voxels in the diagnostic MR images having an ADC above a selected amount are segmented as being in the airway tree.

Segmentation of the airway tree using hyperpolarized noble gases and diffusion weighted magnetic resonance imaging

An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. Drive circuitry for each pair of opposing conductive legs includes a current balun that maintains substantially equal and opposite currents in the two conductive legs. Terminal susceptance elements are used to maintain maximum currents and minimum voltage at the midpoints of the conductive legs. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

RF coil assembly for magnetic resonance imaging and spectroscopy systems

An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. One set of conductive leg pairs is tuned to operate at the Larmor frequency ofC and another set is tuned to operate at the Larmor frequency ofH. Drive circuitry operates the RF coil assembly to produceH spin magnetization which is transferred toC magnetization by the nuclear overhauser effect and to acquire MR data from theC spins. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

Growing community of inventors

Madison, WI, United States of America

Sean Fain