Kamil J Ugurbil

US Patent:

6400150, Jun 4, 2002

Filed:

Apr 2, 2001

Appl. No.:

09/824511

Inventors:

Haiying Liu - Maplewood MN
Wei Chen - Roseville MN
Kamil Ugurbil - Minneapolis MN

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V 300

US Classification:

324307, 324310, 324312, 324309, 324318, 324320

Abstract:

NMR spectroscopy data recovery methods and apparatus for improving the quality of an NMR spectrum are disclosed. The NMR spectrum is improved by acquiring more than the half spin-echo data signal and using an iterative numerical method to reconstruct the missing data points of the corresponding full symmetrical spin-echo data signal. The method includes filtering the initial data signal to extract a low-resolution phase term. The low-resolution phase term is used to form a phase-constrained initial data signal, which is Fourier-transformed to obtain a reconstructed data signal. The reconstructed data signal is modified to include the original spin-echo signal data. The formation of the reconstructed spin-echo data signal and subsequent modification is iterated until convergence is obtained. The reconstructed data signal is then Fourier-transformed to form a reconstructed NMR spectrum.

US Patent:

6639405, Oct 28, 2003

Filed:

Feb 4, 2002

Appl. No.:

10/067180

Inventors:

Haiying Liu - Maplewood MN
Wei Chen - Roseville MN
Kamil Ugurbil - Minneapolis MN

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V 300

US Classification:

324307

Abstract:

NMR spectroscopy data recovery methods and apparatus for improving the quality of an NMR spectrum are disclosed. The NMR spectrum is improved by acquiring more than the half spin-echo data signal and using an iterative numerical method to reconstruct the missing data points of the corresponding full symmetrical spin-echo data signal. The method includes filtering the initial data signal to extract a low-resolution phase term. The low-resolution phase term is used to form a phase-constrained initial data signal, which is Fourier-transformed to obtain a reconstructed data signal. The reconstructed data signal is modified to include the original spin-echo signal data. The formation of the reconstructed spin-echo data signal and subsequent modification is iterated until convergence is obtained. The reconstructed data signal is then Fourier-transformed to form a reconstructed NMR spectrum.

US Patent:

6650116, Nov 18, 2003

Filed:

Sep 24, 2001

Appl. No.:

09/961502

Inventors:

Michael G. Garwood - Medina MN
Kamil Ugurbil - Minneapolis MN
Lance DelaBarre - St. Anthony MN
Patrick Bolan - Minneapolis MN

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V 300

US Classification:

324309, 324307, 324300

Abstract:

A method and system for performing MRI and NMR spectroscopy that improves the dynamic range of the received signal by using adiabatic RF pulses for spin excitation rather than for spin inversion. The preferred adiabatic RF excitation produces a spatially varying phase across the slab, and a sharp slab profile. The phase variation is divided up by a phase-encoding gradient into voxels having a phase variation that is negligible over the width of the voxel. The phase variation in the slab-select direction is, on the whole, large enough that the peak amplitude of the received signal is reduced and the signal width broadened. This reduces the dynamic range required of the analog to digital converter used in a NMR system. A NMR system suitable for carrying out the methods of the invention is also disclosed.

US Patent:

6788056, Sep 7, 2004

Filed:

Jul 31, 2001

Appl. No.:

09/919479

Inventors:

J. Thomas Vaughan - Stillwater MN
Gregor Adriany - Minneapolis MN
Kamil Ugurbil - Minneapolis MN

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V 300

US Classification:

324318

Abstract:

An apparatus comprises a radio frequency magnetic field unit to generate a desired magnetic field. In one embodiment, the radio frequency magnetic field unit includes a first aperture that is substantially unobstructed and a second aperture contiguous to the first aperture. In an alternative embodiment, the radio frequency magnetic field unit includes a first side aperture, a second side aperture and one or more end apertures. In one embodiment of a method, a current element is removed from a radio frequency magnetic field unit to form a magnetic field unit having an aperture. In an alternative embodiment, two current elements located opposite from one another in a radio frequency magnetic field unit are removed to form a magnetic filed unit having a first side aperture and a second side aperture.

US Patent:

6958607, Oct 25, 2005

Filed:

Aug 8, 2003

Appl. No.:

10/637261

Inventors:

J. Thomas Vaughan - Stillwater MN, US
Gregor Adriany - Minneapolis MN, US
Kamil Ugurbil - Minneapolis MN, US

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V003/00

US Classification:

324318

Abstract:

An apparatus comprises a radio frequency magnetic field unit to generate a desired magnetic field. In one embodiment, the radio frequency magnetic field unit includes a first aperture that is substantially unobstructed and a second aperture contiguous to the first aperture. In an alternative embodiment, the radio frequency magnetic field unit includes a first side aperture, a second side aperture and one or more end apertures. In one embodiment of a method, a current element is removed from a radio frequency magnetic field unit to form a magnetic field unit having an aperture. In an alternative embodiment, two current elements located opposite from one another in a radio frequency magnetic field unit are removed to form a magnetic filed unit having a first side aperture and a second side aperture.

US Patent:

6969992, Nov 29, 2005

Filed:

Oct 4, 2004

Appl. No.:

10/957870

Inventors:

J. Thomas Vaughan - Stillwater MN, US
Gregor Adriany - Minneapolis MN, US
Kamil Ugurbil - Minneapolis MN, US
John Strupp - Coon Rapids MN, US
Peter Andersen - Independence MN, US

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V003/00

US Classification:

324318, 324309

Abstract:

An excitation and detection circuit having individually controllable elements for use with a multi-element radio frequency coil. Characteristics of the driving signal, including, for example, the phase, amplitude, frequency and timing, from each element of the circuit is separately controllable using small signals. Negative feedback for the driving signal associated with each coil element is derived from a receiver coupled to that coil element.

US Patent:

7023209, Apr 4, 2006

Filed:

Oct 9, 2001

Appl. No.:

09/974184

Inventors:

Xiaoliang Zhang - Minneapolis MN, US
Kamil Ugurbil - Minneapolis MN, US
Wei Chen - Roseville MN, US

Assignee:

Regents of the University of Minnesota - Minneapolis MN

International Classification:

G01V 3/00

US Classification:

324318

Abstract:

Apparatus and method for MRI imaging using a coil constructed of microstrip transmission line (MTL coil) are disclosed. In one method, a target is positioned to be imaged within the field of a main magnetic field of a magnet resonance imaging (MRI) system, a MTL coil is positioned proximate the target, and a MRI image is obtained using the main magnet and the MTL coil. In another embodiment, the MRI coil is used for spectroscopy. MRI imaging and spectroscopy coils are formed using microstrip transmission line. These MTL coils have the advantageous property of good performance while occupying a relatively small space, thus allowing MTL coils to be used inside restricted areas more easily than some other prior art coils. In addition, the MTL coils are relatively simple to construct of inexpensive components and thus relatively inexpensive compared to other designs. Further, the MTL coils of the present invention can be readily formed in a wide variety of coil configurations, and used in a wide variety of ways.

US Patent:

7279899, Oct 9, 2007

Filed:

Oct 6, 2005

Appl. No.:

11/244815

Inventors:

Shalom Michaeli - St. Paul MN, US
Michael G. Garwood - Medina MN, US
Kamil Ugurbil - Minneapolis MN, US
Dennis J. Sorce - Cockeysville MD, US

Assignee:

Regents of the University of Minnesota - St. Paul MN

International Classification:

G01V 3/00

US Classification:

324318, 324309

Abstract:

This document discusses, among other things, a system and method for modulating transverse and longitudinal relaxation time contrast in a rotating frame based on a train of radio frequency pulses.