Abstract: A transmit coil array assembly for use in a magnetic resonance imaging (MRI) system comprises a plurality of radio frequency (RF) coils arranged in a configuration for transmitting in parallel during transmission mode of the MRI system and a plurality of corresponding RF amplifiers each coupled to a corresponding RF coil for driving currents in the RF coils. The currents are controlled for defining and steering an excitation volume within an examined subject. The currents along with the currents in the gradient coils are further controlled to effect accelerated multi-dimensional excitation. A method for magnetic resonance imaging (MRI) with multiple transmit coils comprises the step of exciting a portion of an examined subject with the multiple transmit coils and the step of receiving magnetic resonance (MR) signals from at least one radio frequency (RF) coil for generating images corresponding to the selected portion of the subject.

Abstract: A method of and system for parallel imaging using a Magnetic Resonance Imaging (MRI) system is provided. The method comprises acquiring a plurality of magnetic resonance (MR) signals from a receiver coil array placed about a subject in the MRI system, where the receiver coil array has a plurality of receiver elements arranged in rows and, during application of a readout gradient in a frequency encoding direction, shifting receiver frequencies by a selectable amount for each row of the array in order to shift a limited field of view (FOV) in the frequency encoding direction.

Abstract: Apparatus (10) for determining the leading edge (E) of an airfoil (A) includes a first light source (S1) illuminating a portion of the airfoil including its leading edge and a first camera (M1) acquiring an image of the illuminated portion of the airfoil. A second light source (S2), spaced apart from the first light source, also illuminates a portion of the airfoil including its leading edge. A second camera (M2) acquires an image of the portion of the airfoil illuminated by the second light source. The location (N2) of the second light source and the first camera are coincident in space as are the location (N1) of the first light source and the second camera. An image processor (P) processes the respective images obtained from the two cameras to locate the leading edge of the object. In doing so, the processor utilizes similarities in illumination of the airfoil by the respective light sources and occlusion boundaries of the respective illuminated portions of the airfoil.

Abstract: A method for generating, in a non-contact range finding and measurement system, a template structure representative of the surface of an observed object, and for utilizing the template structure to synthesize data points in corrupted regions of an image of the object.

Abstract: A digital tomosynthesis system acquires a plurality of projection radiographs of an object and reconstructs structures of the object based on the acquired projection radiographs. The digital tomosynthesis system includes an x-ray source and a detector. The x-ray source emits a beam of x-rays, and moves in a linear trajectory relative to the detector.

Abstract: A parallel Magnetic Resonance Imaging (MRI) system is provided for reconstructing images, to enable accelerated MRI with minimal artifacts. The MRI system comprises an array of magnetic resonance (MR) coils arranged in an array for detecting a plurality of MR signals, each coil having a corresponding spatial sensitivity profile and a processing means for processing the plurality of MR signals with at least one filter bank to reconstruct at least one image.

Abstract: The invention provides a method for sealing arc tubes while preventing cracking of the tube. The method comprises sealing a pair of electrodes on the arc tube in a furnace. A heat shield structure is used to reduce the thermal gradient generated by the sealing process. The heat shield comprises alternating layers of thermally conducting materials and thermally non-conducting materials.

Abstract: A system and computer implemented method for enabling field service of machines and training of field service personnel. The method comprises the steps of generating at least one validated sequence of instructions for at least one maintenance task and delivering the at least one validated sequence for use in performing the at least one maintenance task.

Abstract: An ultra-wideband (UWB) communications system combines the techniques of a transmitted reference (TR) and a multiple access scheme called delay hopping (DH). Combining these two techniques using UWB signaling results in a penalty in signal-to-noise ratio (SNR) over conventional pulse position modulation (PPM) techniques but avoids the synchronization difficulties associated with conventional approaches. The signaling pulse waveforms are designed to insure that their power spectral densities, after any frequency translation to the center of an operating band, are essentially spectrally disjoint with frequencies that must be protected. This TR technique is combined with the DH multiple access technique to create a UWB communications scheme that has a greater multiple access capacity than does the UWB TR technique by itself.

Abstract: A radio frequency (RF) detector array and a MRI system are provided. The detector array comprises a plurality of conductive array elements being substantially parallel to a conductive ground plane, a plurality of capacitors, wherein at least one capacitor is shunted from each array element to the ground plane to adjust a corresponding electrical length of each conductive array element, and, wherein a combination of each respective array element, at least one corresponding capacitor and the ground plane forms a resonator that resonates at a selected frequency. The detector array further a decoupling interface, and a plurality of matching boxes for matching each decoupled conductive strip to a selected impedance. A MRI system is provided including a detector array as described herein to produce MR images of the object to be imaged.

Abstract: A magnetic resonance imaging (MRI) method is described. The method includes simultaneously acquiring partial radial backprojection signals from a cylindrical array of m detectors surrounding an object, generating, in a k-space, additional backprojection signals with decimated b-fold backprojection steps. The generating includes producing 2-dimensional (2D) spatial harmonics to replace the decimated b-fold backprojection steps. The producing includes assuming that a sum of weighted sensitivity profiles of at least one of the detectors is a function of an angle between a vector k and an axis kx of the k-space and a function of a radius of a cylindrical surface formed by the array of detectors. The angle is an angle along which reconstruction of an image of the object is performed.

Abstract: A method of improving images is provided. A body of image data is collected and signal to noise (SNR) values thereof are determined. The collected data is converted into an electronic image representation X. Image X comprises a first array of pixel intensity values. Further, a low pass filtered image representation F comprising a second array of pixel intensity values is obtained. An improved electronic image representation P comprising a third array of pixel intensity values is generated by replacing each pixel intensity value of electronic image representation X by a linear combination of the replaced pixel intensity value from image X and the corresponding pixel intensity value from image F. An array of linear combination coefficients &agr;, (1−&agr;) determine the relative contributions of the replaced X pixel intensity value and the value of the corresponding pixel intensity from image F, respectively.

Abstract: A method for shimming a magnetic field of a magnet in a volume of interest, utilizing ferromagnetic pellets for shimming. The pellets are positioned in a nonmagnetic holder having a predetermined number of pellet holes. The method includes measuring the magnetic field of a magnet in a plurality of locations within the volume of interest, determining a nominal passive shimming mass to compensate the measured magnetic field to approximate a desired magnetic field within the volume of interest; and placing a combination of ferromagnetic pellets from a selection of full strength pellets, nearly full strength pellets, and low strength pellets in the pellet holes to approximate the nominal passive shimming mass.

Abstract: A method and apparatus are provided for performing a contrast-based dynamic range management (C-DRM) algorithm. The apparatus comprises an C-DRM processor that performs the C-DRM algorithm of the invention in order to compress an image input to the C-DRM processor down to a desired gray scale range for observation on a display. The C-DRM processor decouples adjustment of image mean values (low frequency) and image contrast values (high frequency), and manages mean and contrast separately. The use of separate mean and contrast modification functions improve on other known compression techniques by providing a more deterministic behavior and reduced complexity, allowing, for example, independent management of negative and positive contrasts. The C-DRM processor can also automatically adapt to the dynamic range of an input image so that the input image thereby applying the minimal compression needed to display the image.

Abstract: A cycle skipping power control apparatus comprising: a power controller adapted for receiving a power command and a switch closure feedback signal and for generating a high resolution pulse command; and a pulse generator adapted for receiving the high resolution pulse command and, optionally, the power command, and generating a compensated enable pulse and the switch closure feedback signal.

Abstract: Flash artifacts in ultrasound flow images are suppressed to achieve enhanced flow discrimination. Flash artifacts typically occur as regions of elevated signal strength (brightness or equivalent color) within an image. A flash suppression algorithm includes the steps of estimating the flash within an image and then suppressing the estimated flash. The mechanism for flash suppression is spatial filtering. An extension of this basic method uses information from adjacent frames to estimate the flash and/or to smooth the resulting image sequence. Temporal information from adjacent frames is used as an adjunct to improve performance.

Abstract: An method for automatically extracting a three-dimensional sub-structure, for example a coronary vessel tree, from a plurality of slice images comprises the steps of depositing a seed point within a selected region of interest and segmenting the plurality of slice images responsive to the deposition of the seed point. The segmentation is performed in accordance with a plurality of predetermined classification values to extract the three-dimensional sub-structure. A method for automatically segmenting comprises the steps of receiving a deposited seed point, extracting a plurality of desired regions within the sub-structure and generating a segmented sub-structure from the extracted desired regions.

Abstract: A method for increasing the dynamic light intensity range of an image by combining pixel data from multiple images collected at different levels of illumination intensity to create a single floating-point image representation of an observed scene.

Abstract: The present invention is directed to an imaging apparatus for examining an object having smooth surfaces to determine shape deformations in the surface of object. The imaging apparatus includes an imaging device for obtaining a scanned image of the object to be examined. A reference image of the object is stored in a memory. An image register is coupled to the imaging device and to the memory containing the reference image of the object. The image register stores patch information corresponding to both the reference image and the scanned image. A transformation estimator is coupled to the image register, and provides a transform for registering the scanned image to the reference image. A deformation estimator is coupled to the transformation estimator and to the image register. The deformation estimator is configured to utilize the transform and the patch information to determine shape deformations of the object.

Abstract: A method for segmenting an input volume in accordance with at least one selected characteristic comprises the steps of casting a plurality of rays along a plurality of views of the input volume, identifying regions corresponding to the selected characteristic within each ray, and processing the identified regions to generate an output volume indicating regions having the selected characteristic.