Leland Stanford Junior University

M2m Imaging Corporation

General Electric Company

University of California

Greig Scott

Kamal Vij

Erzhen Gao

Ingmar Viohl

Jon T DeVries

Joseph R Flicek

Shreyas S Vasanawala

Fraser Robb

Thomas Grafendorfer

Norbert Joseph Pelc

Steven M Conolly

Lei Xing

Rebecca Fahrig

James S Tropp

Paul J Keall

Amit Ramakant Sawant

Kim Butts Pauly

William Ryan Overall

Paul David Calderon

Marta G Zanchi

In accordance with various embodiments, a radio frequency (RF) coil array for use in a magnetic resonance imaging (MRI) system includes at least first and second RF coils. Each of the RF coils have a main body loop configured to at least one of transmit or receive RF energy at an operating imaging frequency in connection with acquiring MRI image data for an MRI system. The RF coil array also includes first and second cables configured to electrically couple the first and second RF coils, respectively, to a system interface. The RF coil array also includes a common ground connection between the first and second cables. The common ground connection is selectively positioned at a grounding point along lengths of the first and second cables to form a ground loop having a select self-resonance frequency (SRF) that differs from the imaging frequency of the MRI system.

Radio-frequency coil arrays and methods of arranging the same

A system and method for generating preamplifier feedback in magnetic resonance imaging (MRI) systems are provided. A preamplifier arrangement for the MRI system includes a plurality of preamplifiers with each of the preamplifiers connected to a different channel of a multi-channel coil array of the MRI system. The preamplifier arrangement further includes a feedback network connected to each of the plurality of preamplifiers with each of the feedback networks configured to generate negative feedback at one or more oscillation frequencies.

System and method providing preamplifier feedback for magnetic resonance imaging

The present invention provides a radiotherapy treatment apparatus that includes a treatment beam, a magnetic field disposed parallel collinear to the treatment beam, and a target that is disposed along the treatment beam. The treatment beam can be a charged particle beam, a proton beam, an electron beam, or a linear accelerator (Linac) beam. The magnetic field is from a magnetic resonance imager (MRI), a megavolt x-ray imager, or a kilovolt x-ray imager and is disposed to operate in coordination with operation of the treatment beam and to narrow the beam. The tumor is disposed to rotate with respect to the treatment beam and the magnetic field, or the treatment beam and the magnetic field are disposed to rotate up to 360&#xb0; with respect to the target when mounted to a ring gantry. The apparatus can include a rotation angle dependent shim disposed to account for Earth's magnetic field.

Configurations for integrated MRI-linear accelerators

A method for detecting coupled RF current magnetic resonance (MR) objects in a body and determining MR risk is provided. The body is scanned with reverse circularly polarized RF. MR signals generated by coupling of the reverse circularly polarized RF with the RF current MR objects are detected. The detected MR signals are used to determine a risk value.

Reverse circularly polarized non-tissue damaging RF in MRI detection of coupled RF current producing objects in a body

An amplifier system providing improved Cartesian feedback is provided. A complex band pass error amplifier is provided. A quadrature up converter is connected to the complex band pass error amplifier so as to receive as input, output from the complex band pass error amplifier. An amplifier is connected to the quadrature up converter so as to receive as input, output from the quadrature up converter. A quadrature down converter is connected at or beyond the amplifier output so as to receive as input a signal proportional to that delivered by the amplifier as output to a load, wherein the complex band pass error amplifier is connected to the quadrature down converter so as to receive as a first input, output from the quadrature down converter and as a second input, a quadrature reference signal.

Frequency offset Cartesian feedback system

A radio frequency coil array () includes at least first () and second () receive coils. A flux pipe () includes electrically connected first () and second () loop coils. The first () and second () loop coils are coupled to the respective first and second receive coils. The flux pipe () reduces mutual inductance between the first () and second () receive coils.

Coil decoupling in magnetic resonance imaging

An apparatus for use in a magnetic resonance examination includes a radio frequency receive coil () and adjustable tuning circuitry () for adjusting the resonant frequency of the receive coil. The apparatus also includes a preamplifier () which amplifies signals generated by the receive coil. An adjustable feedback circuit () alters an effective Q of the receive coil.

Bandwidth expansion in magnetic resonance

A magnetic resonance imaging system includes a primary magnet and a secondary magnet operable to produce magnetic fields within a sample being imaged. The MRI system further includes at least one RF coil that is operable to receive electromagnetic frequencies from the sample. The RF coil is formed from tubing that serves as a cooling conduit through which flows a cooling fluid provided by a cooling source. The cooling fluid cools the RF coils to improve imaging of the sample.

In a MRI system having a FID detector unit and a computer unit for processing FID signals, phase errors introduced into the FID signal at the detector unit are corrected at the computer unit by transmitting a pilot signal from the computer unit to the detector unit, processing the pilot unit along with a detected FID signal at the detector unit, transmitting the processed signals to the computer unit, obtaining the pilot signal and FID signal at the computer unit, and combining the pilot signal and the FID signal whereby phase errors cancel.

Synchronization of wireless transmitted MRI signals in MRI system

A device and method with miniature and tunable MRI receiver coil for catheters is provided that can be used in minimally invasive procedures and intravascular imaging. An MRI receiver coil for catheter procedures is provided having an impedance matching element that includes at least one miniature transmission line cable which are interconnected to construct the impedance matching element. In a particular embodiment, the miniature transmission line cables are constructed to make an inductance matching element defining an inductance L. In another particular embodiment, the miniature transmission line cable is a capacitance matching element defining a capacitance C. The present invention provides a system and method that allows local fine-tuning with a higher signal-to-noise ratio. Transmission line cables also overcome the minimum size limits of fixed components. The shielded and balance techniques further reduce noise and improve safety.

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Palo Alto, CA, United States of America

Greig Scott