Abstract: A method of registering a plurality of functional images includes providing a plurality of functional images, providing a plurality of structural images, each one of which having a known positional relationship to at least one of said plurality of functional images, and finding a first mapping transformation between pairs of functional images based on the first mapping transformation and the positional transformation.

Abstract: A method of using magnetic resonance imaging (MRI) systems for acquiring separate data contributions in images of subjects derived from at least a first and a second spectral components, the method comprising: applying RF pulses; receiving RF signals with a phased array coil arrangement having a plurality of segments; acquiring two initial complex images, the first of the two initial images being a complex image of each of the spectral components in phase; the second of the two initial images being a complex image of each of the spectral components out of phase, the first of said two initial complex images ostensibly being a plus image, and the second of said two complex images ostensibly being a minus image initially; and matching the ostensible plus and minus images so that the first complex images and the second complex images are grouped together for further processing. Preferably, a two-point Dixon method is used to generate the components.

Abstract: A computerized tomography system wherein the X-ray source rotates about the subject and moves axially relative to the subject to provide a helical scan. A detector array includes a plurality of rows of detector elements extending axially and each element being of the same size to enable the acquisition of multiple planar data per rotation. The acquired data is reformatted into planar data by interpolating as a function of both the axial subject position and the axial detector element position.

Abstract: This invention is concerned with actively shielded magnetic resonance (MR) devices and more particularly with an improved system which includes only a single former. All the coils of the system those with backward current and those with forward current, can all be wound in a single process on a single former machined during a single installation.

Abstract: A method for performing motion-compensated spectral-spatial selective magnetic resonance imaging. The method includes applying a radio frequency (RF) spectral-spatial excitation pulse sequence to a region of a body. The excitation sequence includes a binomial pulse train including at least two sub-pulses. The binomial pulse train also provides spectrally selective excitation of a selected resonance frequency at the predetermined field strength. The method also includes applying to the same body region an oscillating slice selection gradient so that each sub-pulse of the binomial pulse train is applied during portions of the oscillating gradient having the same polarity. The oscillating gradient further includes at least one extra gradient switch added to the end of the oscillating gradient for providing a balanced gradient for inherently motion-compensated slice selection.

Abstract: A method of registering a plurality of functional images using both structural images and gating.

Abstract: A magnetic resonance angiography method for acquiring angiographic images using any or all of three different types of selective presaturation pulses to the particular parts of the body for enhancing vascular imaging. The three types are:1) an inversion pulse applied prior to the application of a burst of RF pulses used for tipping the spins designed to eliminate signals from unwanted blood entering the field of view being imaged,2) inversion pulses applied between the first inversion pulse and the first of the Rf pulses used to suppress blood not properly suppressed by the first type of suppression pulses, such as fast flowing blood, and3) saturation pulses applied within the burst of RF pulses to suppress signals from slow flowing blood when in the 2D acquisition mode. Special heart and breath gating methods are also described that enable good compromises between image quality and scan time.

Abstract: A dual headed gamma camera arrangement wherein a first head is juxtaposed to a second head to define an angle therebetween.

Abstract: This invention is concerned with magnetic resonance imaging (MR) systems and more particularly with special MRI systems which enable rotating the data acquisition apparatus of the MRI system. Such systems enables imaging different body parts at a variety of angles; thus providing better diagnostic possibilities.

Abstract: An MRI system incorporating modular whole body gradient coils that can selectively be used for conventional imaging or for ultra-fast imaging. A central modular coil is used alone for the ultra-fast imaging or used in combination with a modular flanking coil for conventional imaging.

Abstract: A method of acquiring an analog electrical pulse signal caused by a radiation event impinging on a detector crystal and viewed by a plurality of detector units. An image is formed based on a plurality of the events, each of which is captured by some of the detector units. The method of acquiring includes.(a) adding a linearity enhancement signal to the analog signal; and(b) converting the analog signal to a digital signal, where the linearity enhancement signal is slowly varying relative to the length of an analog signal pulse. Alternatively or additionally, a resolution enhancement signal is added to the analog signal before (b) converting the analog signal to a digital signal. The resolution enhancement signal varying relatively quickly compared to the length of an analog signal pulse.

Abstract: This invention is concerned with actively shielded magnetic resonance (MR) devices and more particularly with protecting such systems in the event of a quench by preventing changes in the stray field outside the magnetic devices. The invention includes dividing the system's coils into groups each comprised of inner and outer coils and arranged so that the net dipole moment, and the contribution to stray field from each group is always close to zero. Each group is connected in parallel to a protective unit, for example a resistor, so that the excess current can flow through the protective unit in the event of a quench; thus avoiding the burnout of the system's coils.

Abstract: A super-conducting magnet for magnetic resonance imaging systems comprising symmetrically located back-to-back C-frame magnets.

Abstract: Radio frequency interference (RFI) shielding for use with magnetic resonance imaging (MRI) systems wherein the magnet of the system is coupled to the shielding to form an integral part thereof.

Abstract: A nuclear medicine diagnostic imaging system wherein the gamma camera rotates about the patient and is coupled to receive electrical power, control signals and to transmit data using cableless coupling means. This enables the system to provide whole body helical scans. Reconstruction begins during the first revolution of the camera about the patient and continues during subsequent revolutions to provide evolving images.

Abstract: A super conducting magnet system for magnetic resonance systems comprising at least one radiation shield. Temperature sensors, an external refrigeration system and a controller are provided for maintaining said at least one shield at a constant temperature by heating the shield and reducing the heat provided as the refrigerator system wears or by increasing the frequency of the refrigeration cycle as the system wears or both.

Abstract: A system for recording fewer of the events that are caused by unwanted photons with greater stability. The system locally determines the energy spectrum and fits for each pixel of the image the determined energy spectrum with a modified trial function composed of: a photopeak component of known energy shape, Compton scatter components having theoretically derived energy shapes and, when applicable, also measured or calculated energy spectra of other unwanted photons. The modified trial function also takes into consideration unknown local deviations in the outputs of electronic components. The amplitude of the photopeak distribution resulting from the fit is used to obtain the local content of wanted interactions in the image. This enables removal of Compton contamination and also the contamination caused by interaction of the gamma photons with lead components.

Abstract: A magnet for MRI systems having a first pair of spaced apart oppositely disposed walls with a first pole piece extending from one wall of said first pair of walls towards a second pole piece extending from the other wall of the pair of walls with an air gap between the first and the second pole pieces. A superconducting coil mounted on at least one of the first and the second pole pieces to generate a magnetic field between the pole pieces with the air gap between the pole pieces large enough for receiving a patient therein fop magnetic resonance imaging purposes; and a second pair of oppositely disposed walls closing said magnetic circuit; there being sufficient room between the walls to enable medical personnel to be between the walls of the second pair of walls and the pole pieces providing substantially complete access to the patient in the air gap.

Abstract: A system for reducing afterglow induced artifacts by filtering out afterglow using recursive filters that are tailored to match the intensity and decay time of the scintillating detectors that produce the afterglow.

Abstract: An interpolation filter that enables interpolation without changing the values of the interpolated points coinciding with the sampled data points, the signal content of the original image, or the variance of the original image.