General Electric Company

Ge Medical Systems Global Technology Company, LLC

The United States of America As Represented by the Secretary of

Robert Michael Vavrek

David E Dean

Scott Thomas Mansell

Thomas G McFarland

Ceylan Celil Guclu

Christopher C Myers

Ricardo Becerra

Daniel Joseph Schaefer

Gopal Biligeri Avinash

William A Edelstein

Gary H Glover

Sayed-Amr A El-Hamamsy

John Norton Park

Graeme Colin McKinnon

Peter B Roemer

Otward M Mueller

Robert Adolph Ackermann

Robert Arvin Hedeen

Paul Shadforth Thompson

Joseph K Maier

Mark Lloyd Miller

Bruce Campbell Amm

William F Wirth

Rakesh Mohan Lal

Phillip Edward Steen

Dewain Anthony Purgill

Richard Philip Mallozzi

Dennis H Pritzkow

John Peter Fura

Timothy William Skloss

Robert G Turner

Mike James Radziun

Nancy S Grigsby

Imran A Bajwa

Certain embodiments of the present invention relate to a signal-to-noise ratio dependent image processing system. The method includes computing at least one SNR for at least one region of an image, determining a filter parameter for at least one region based on the at least one SNR, and processing at least one region of the image based on the filter parameter. In addition to SNR, a filter parameter may be determined using user preferences. The system includes a signal-to-noise ratio processor for determining a signal-to-noise ratio for an image. The system also includes a parameter selection unit for selecting at least one filter parameter based on the signal-to-noise ratio. The system further includes an image filter for filtering the image based on the filter parameter(s). In an embodiment, the SNR processor determines signal-to-noise ratio(s) for region(s) in the image.

Method and apparatus for signal-to-noise ratio dependent image processing

The present invention provides a system and method of improved homogeneity whereby at least a portion of an RF coil is filled with homogeneity enhancing material. Disposing the homogeneity enhancing material, such as perfluorocarbon, within the RF coil, implementation of thick saturation pads may be avoided altogether or thinner pads may be used to fill any voids between the patient and the coil. The present invention is particularly useful in a CTL coil assembly for acquiring diagnostic data of the neck region of a patient. However, the advantages achieved by the present invention may be incorporated into other surface coils for other anatomical regions where control of the susceptibility is desired. Additionally, the homogeneity enhancing material also acts as a heat sink for any hot spots on the coil.

RF coil embedded with homogeneity enhancing material

A system and method for mimicking a human brain for MR imaging at various magnetic field strengths is disclosed. A phantom is constructed of a structure having a number of sections. A first section contains a mixture of nickel chloride, agarose gel powder, potassium sorbate, deuterium oxide, and water such that the T1, T2, and proton density values of the first section mimic white matter of the human brain. A second section contains different amounts of the same components such that the T1, T2, and proton density values of the second section mimic gray matter of the human brain. As such, when the phantom is scanned in an MR imaging machine, an optimized flip angle for T1-weighted imaging to improve contrast between white matter and gray matter of the human brain that takes into account proton density differences therebetween can be determined.

Apparatus to simulate MR properties of human brain for MR applications evaluation

The present invention provides for a method for using a silicon dioxide (SiO) material that is equally effective in improving magnetic field homogeneity during MR imaging. The present invention further provides for using silicon dioxide in its granular state. The granular silicon dioxide can then be poured inside a flexible container and the flexible container can be formed to fit any contour of the body.

Method and apparatus for enhanced fat saturation during MRI

A method for decreasing gradient field pulse sequence duration for a magnetic resonance imaging system, the method comprising: establishing an allowable gradient field strength for an axis of a plurality of axes for a field of view; applying a weighting factor associated with each axis of the plurality of axes; establishing a slew rate responsive to a selected axis of the plurality of axes that exhibits a largest gradient field strength in light of the weighting factor and the field of view; and operating the plurality of axes at the largest gradient field strength.

Gradient coil apparatus for magnetic resonance imaging

A technique for reducing acoustic noise emitted by a magnetic resonance imaging system includes providing energy dampening elements in the scanner, such as within the gradient coil assembly, between the gradient coil assembly and the primary magnet, and around the outer and inner peripheries of the primary magnet and RF coil. The elements may be formed to conform to the structures of the scanner, and may be tile-like elements which can be fitted to new scanners and retrofitted to existing equipment.

Method and apparatus for reducing acoustic noise in MRI scanners

A low noise imaging apparatus for producing Magnetic Resonance (MR) images of a subject and for substantially minimizing acoustic noise generated during imaging is provided. The imaging apparatus comprises a magnet assembly, a gradient coil assembly, and a rf coil assembly, wherein at least one of the magnet assembly, the gradient coil assembly and the rf coil assembly are configured to reduce the generation and transmission of acoustic noise.

Low noise MRI scanner

An NMR imaging system includes an apparatus for producing a magnetic field gradient within an imaging volume into which the object being imaged is placed. The relatively linear region of the magnetic field gradient is adjusted depending upon the size of the object. The apparatus comprises a source of a gradient signal and four saddle coils positioned in quadrant of a sheet that is wrapped around a cylindrical form. Each saddle coil has a spiral shaped conductive pattern on which are located a primary termination point and a pair of secondary termination points. A switch mechanism connects the four saddle coils in series with the source of a gradient signal, so that voltage from the gradient signal is applied between the primary termination point and a selected secondary termination point of each saddle coil. A control signal applied to the switch mechanism indicates selected secondary termination point and the signal varies according to the size of the object.

Multiple tap gradient field coil for magnetic resonance imaging

A local gradient coil adapted for use with stereotaxic devices includes an opening in the coil form positioned to minimize the disruption to the gradient fields and a bearing for moving the form with respect to the stereotaxic frame so that the opening may be limited in area and yet provide essentially unrestricted access to the patient. The windings in the neighborhood of the opening may be diverted by modifying the stream function of the windings in a manner to minimize the effect of the opening on the gradient field.

Surgical local gradient coil

A gradient amplifier for use in magnetic resonance imaging equipment employs a low voltage DC power supply connected in series between a pair of higher voltage DC power supplies, the latter supplies serving to provide increased power for rapid gradient switching and the former supply providing correction current to produce the desired voltage output. The high voltage DC power supplies preferably comprise multiple DC units which can be combined to provide finer steps of control prior to correction by the lower voltage supply. The low voltage DC power supply preferably comprise one or more linear amplifiers connected in series, or one or more switchmode amplifiers connected in series. The DC power supplies are controlled in an open loop manner from a gradient signal that designates the desired current for the gradient coil and the amplifiers are operated in a closed loop responding to to a feedback signal from the gradient coil.

Split gradient amplifier for an MRI system

A compact local gradient coil is combined with a local RF coil to provide lower powered, higher strength gradient fields and faster gradient response as is useful in magnetic resonance imaging. Interference between the RF coil and gradient coil is minimized by placement of the gradient coil external to the RF coil and by gradient coils that are axially symmetric and/or have conductors substantially orthogonal to the RF coil conductors. Acoustic noise in these smaller, stronger coils is reduced with ports cut into the coil forms.

Local gradient coil

An image data set acquired by an NMR system using an echo-planar pulse sequence is corrected for systemic errors. Errors are measured by acquiring a reference data set using the same echo-planar pulse sequence without phase encoding, and the measured errors are employed to correct phase errors in the image data set.

Correction of NMR data acquired by an echo-planar technique

A magnetic resonance imaging system uses a pool of amplifiers to generate gradient signals. Each amplifier within the pool may be switched among any of the gradient axes, so as to efficiently allocate amplifier power among the gradients. In one embodiment, the amplifiers of the pools are connected in stacks by an input and output matrix comprised of mechanical switches driven in tandem by interlocked motors. The switches connect the outputs of the amplifiers in series. The input signal is 'boot strapped' through the amplifier stack to provide proper signal level.

Gradient amplifier system with flexible amplifier allocation

A shielded room for containment of magnetic fringe fields generated by a magnet which forms part of an NMR scanner system utilizes wall members having a thickness proportional to the amount of flux conducted. In the preferred embodiments, the shielded room can have one of rectangular, cylindrical, or polygonal geometries, for example. The walls (floors and ceilings) are constructed from staggered plates to have increased thickness where flux is greatest, and correspondingly decreased thickness where the flux is lowest. The shielded room can be, additionally, provided with end-cap elements in the walls perpendicular to the base of the magnet. Preferentially, the end-cap elements are angled away from the side wall members toward the center of the room to more closely follow the flux path.

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Waukesha, WI, United States of America

Robert Michael Vavrek