THOMAS M GRIST, MD
Radiology at Highland Ave, Madison, WI

5713358, Feb 3, 1998

Mar 26, 1996

8/622718

Charles A. Mistretta - Madison WI
Frank R. Korosec - Madison WI
Thomas M. Grist - Madison WI
Richard Frayne - Madison WI
Jason A. Polzin - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

A61B 5055

1286532

A dynamic MRA study of a subject is performed using a 3D fast gradient-recalled echo pulse sequence. The frame rate of the resulting series of reconstructed images is increased by sampling a central region of k-space at a higher rate than the peripheral regions of k-space. Image frames are reconstructed at each sampling of the central k-space region using the temporally nearest samples from the peripheral k-space regions.

6556856, Apr 29, 2003

Sep 18, 2000

09/664152

Charles A. Mistretta - Madison WI
Thomas M. Grist - Madison WI
Timothy J. Carroll - Madison WI
Jiang Du - Madison WI
Walter Block - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

A61B 5055

600420, 600410, 600419, 324306, 324307, 324309

A magnetic resonance angiogram (MRA) is acquired using a contrast enhancement method in which a series of low resolution NMR images are rapidly acquired during a time resolved phase of the examination in which the contrast bolus makes a first pass through the arteries and veins. Additional, high spatial resolution NMR image data is acquired in a subsequent steady-state phase of the examination. The low resolution NMR image is segmented and masked to depict only arteries, and the central k-space region of this data is combined with the peripheral k-space data portion of the high resolution NMR data to produce one or more images.

6794867, Sep 21, 2004

Jun 13, 2003

10/461227

Walter F. Block - Madison WI
Thomas M. Grist - Madison WI
Aiming Lu - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

G01V 300

324307, 324309

Two images are acquired using a three-dimensional projection reconstruction, SSFP pulse sequence. Different RF phase cycling patterns are used to acquire each image and a fat suppressed water image is produced by combining the two images. Data acquisition efficiency is increased by aquiring k-space data during substantially the entire readout gradient waveform produced during the SSFP pulse sequence.

7508212, Mar 24, 2009

Aug 20, 2007

11/841201

Sean B. Fain - Madison WI, US
Matthew G. Erickson - Madison WI, US
Krishna N. Kurpad - Madison WI, US
James H. Holmes - Madison WI, US
Thomas M. Grist - Madison WI, US

Wisconsin Alumni Research Foundation - Madison WI

G01V 3/00

324318, 324322

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 of C and another set is tuned to operate at the Larmor frequency of H. Drive circuitry operates the RF coil assembly to produce H spin magnetization which is transferred to C magnetization by the nuclear overhauser effect and to acquire MR data from the C spins. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

7146282, Dec 5, 2006

May 6, 2005

11/124599

Daniel W. van der Weide - Madison WI, US
Charles A. Paulson - Clearlake MN, US
Thomas M. Grist - Madison WI, US
Modhurin Banerjee - Madison WI, US

Wisconsin Alumni Research Foundation - Madison WI

G06F 19/00, G01R 27/00

702 56, 702 65

Localized magnetic fields are measured at frequencies into the microwave (GHz) regime using a conductive loop that is integrated on a vibratable member, such as a cantilever. Driving an alternating current at a first high frequency through the loop produces a high frequency alternating magnetic dipole at the same frequency as the current, with the alternating magnetic dipole normal to and centered within the loop. The alternating magnetic dipole at the center of the loop mixes with a sampled alternating magnetic field at a second high frequency at the center of the loop, resulting in application of a mechanical force to the loop and vibratable member. The vibratable member vibrates when the difference between the frequency of the loop current and the frequency of the sampled alternating magnetic field equals the resonant frequency of the vibratable member.

5500596, Mar 19, 1996

Apr 28, 1994

8/234888

Thomas M. Grist - Madison WI
Marcus T. Alley - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

G01R 3328

324318

A local coil for use with an MRI system to acquire images of a patient's legs includes a vertically disposed central coil positioned between the legs, and a pair of horizontally disposed flange coils positioned above and below the legs. In one embodiment of the central coil is a phased array of two coils, and the four coils are connected to the respective inputs of a four channel receiver, and in a second embodiment, the signals from the three coils are combined before application to the input of a single-channel receiver.

6044290, Mar 28, 2000

Apr 6, 1998

9/055503

Karl K Vigen - Madison WI
Charles A Mistretta - Madison WI
Thomas M Grist - Madison WI
Frank R Korosec - Madison WI
Richard Frayne - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

A61B 5055

600419

A dynamic MRA study of a subject is performed using a 3D echo-planar imaging pulse sequence. Four phase encoding views are acquired for each pulse repetition period (TR) and this enables higher resolution images to be acquired without a reduction of temporal frame rate or a loss of image CNR.

5881728, Mar 16, 1999

Jul 26, 1996

8/686795

Charles A. Mistretta - Madison WI
Thomas M. Grist - Madison WI
Richard Frayne - Madison WI
Frank Korosec - Madison WI

Wisconsin Alumni Research Foundation - Madison WI

A61B 5055

1286534

A dynamic MRA study of a subject is performed using a 3D fast gradient-recalled echo pulse sequence. The frame rate of the resulting series of reconstructed images is increased by sampling a central region of k-space at a higher rate than the peripheral regions of k-space. Artifacts caused by variations in signal strength as the contrast agent enters the region of interest are reduced by renormalizing the acquired data. 2D image frames are reconstructed using planes passing near the center of k-space to enable the operator to select which 3D data sets should be used to reconstruct diagnostic images.

5830143, Nov 3, 1998

Jan 21, 1997

8/787181

Charles M. Mistretta - Madison WI
Frank R. Korosec - Madison WI
Thomas M. Grist - Madison WI
Richard Frayne - Madison WI

Wisconsin Alumnin Research Foundation - Madison WI

H61B 5055

600420

A dynamic MRA study of a subject is performed using a 3D fast gradient-recalled echo pulse sequence that employs a non-selective RF excitation pulse. The frame rate of the resulting series of reconstructed images is increased by sampling a central region of k-space at a higher rate than the peripheral regions of k-space. The acquisition is gated using a cardiac trigger signal and the central region of k-space is acquired during diastole and the peripheral regions of k-space are acquired during systole. Image frames are reconstructed at each sampling of the central k-space region using the temporally nearest samples from the peripheral k-space regions. Two of the image frames are subtracted to form an MR angiogram.