University of Minnesota

J Thomas Vaughan

Jinfeng Tian

Michael G Garwood

Kamil Ugurbil

Steen Moeller

Gregor Adriany

Anand Gopinath

Pierre-Francois Van De Moortele

Heather Diane Orser

Carl J Snyder

Peter M Anderson

Lance DelaBarre

Can E Akgun

John Strupp

Peter M Andersen

Djaudat S Idiytullin

Sung Min Sohn

Chris E Olson

Michael Kozma

Daniel P Myer

Peter Andersen

Lance Delabarre

Chris Olson

A radio frequency amplifier system for a magnetic resonance imaging (MRI) apparatus has a radio frequency power amplifier configured to transmit a B1 radiofrequency signal to a patient coil present in the MRI apparatus and a first directional coupler that splits the B1 signal from the amplifier into a transmitted B1 signal and a B1 error signal. A circulator transmits the transmitted B1 signal to a patient coil, and receives and transmits a reflected B1 signal and an MRI signal from the patient coil. The signals received from the patient coil are fed to a control loop. The components of the control loop modify the B1 error signal so that the B1 error signal cancels the B1 reflected signal such that the transmitted signal consists only of the MRI signal without a B1 signal, which is then sent to a low noise MRI signal amplifier and on for diagnostic analysis.

Radio frequency power amplifier system for magnetic resonance imaging

Systems and methods for simultaneous radio frequency ('RF') transmission and reception for nuclear magnetic resonance applications, such as magnetic resonance imaging ('MRI') are described. The system includes a simultaneous transmit and receive (&#x201c;STAR&#x201d;) control system that compensates for the effects of load changes in a radio frequency (&#x201c;RF&#x201d;) coil due to the inevitable motion of living subjects (e.g., from subject motion, respiration, swallowing). The system also maintains a high transmit-receive isolation, even when scanning a subject using a continuous RF broad band sweep excitation.

System and method for simultaneous radio frequency transmission and reception in magnetic resonance imaging

A magnetic resonance system is disclosed. The system includes a transceiver having a multichannel receiver and a multichannel transmitter, where each channel of the transmitter is configured for independent selection of frequency, phase, time, space, and magnitude, and each channel of the receiver is configured for independent selection of space, time, frequency, phase and gain. The system also includes a magnetic resonance coil having a plurality of current elements, with each element coupled in one to one relation with a channel of the receiver and a channel of the transmitter. The system further includes a processor coupled to the transceiver, such that the processor is configured to execute instructions to control a current in each element and to perform a non-linear algorithm to shim the coil.

High field magnetic resonance

An RF coil adjacent an imaging region includes a plurality of conducting coil elements, with each conducting coil element including a proximal portion and a distal portion. The RF coil also includes a capacitance between the distal portions of the at least two conducting coil elements. A mutual coupling inductance between at least two conducting coil elements of the plurality of conducting coil elements is substantially cancelled by the capacitance between the distal portions of the at least two conducting coil elements.

Coil element decoupling for MRI

Growing community of inventors

Minneapolis, MN, United States of America

J Thomas Vaughan