Abstract: A method for regulating a scan dosage includes generating an initial technique command based on default patient size or the previous exposure and on completion of exposure, receiving the actual technique signal. A target entrance dose signal is determined based a default patient size, and tube current is regulated in response to the target entrance dose signal and dose feedback. Image brightness is independently controlled in response to the target entrance dose and average image brightness. An object size is estimated based on the actual technique signal and an image brightness feedback. An optimized generator technique is defined based on estimated object size to achieve a target image quality for the user selected contrast material.

Abstract: An MRI system includes an array of series resonant transmit elements 6 and 65 including individual control of RF current in all elements 106, 108, 110, 114, 116, 118, 120. The array 6 and 65 adjusts scan homogeneity during a scan or prescan phase by adjusting amplitude and phase. The array 6 and 65 also selectively excites areas of interest, thus avoiding major power dissipation and avoiding heating in the patient.

Abstract: A method of excitation for use during an NMR examination includes the subjecting of a body (92) to an orienting magnetic field (B0). The body (92) is adiabatically conditioned with a first series of Rf pulses (IP1–IPn). The body (92) is excited with a second series of RF pulses (E1–Em) in a presence of gradient field pulses. A resonance signal is emitted from the body (92) in response to the second series of RF pulses (E1–Em).

Abstract: An HV connector for high power X-ray device consists of thermally conductive epoxy, cable terminal, faraday cup, spring-loaded contact, and lead lined housing. The thermally conductive epoxy includes fillers. The epoxy can also be loaded with gravels of similar materials. A Faraday cup is included in the center area to offer electric field relief. Spring-loaded contacts are included for the easiness of pin alignment and robustness of handling. An efficient thermal management solution is accomplished through proper selection of thermal conductivities of gasket and epoxy.

Abstract: A Magnetic Resonance Imaging (MRI) system 50 is provided including a superconducting magnet coil assembly 54. The magnet coil assembly 54 includes a superconducting magnet 82 and forms an imaging volume 60. The superconducting magnet 82 generates a polarizing field in the imaging volume 60. A readout magnet 106 generates a readout field in the imaging volume 60. A controller 102 is electrically coupled to the readout magnet 106 and pulses the readout magnet 106 to generate a uniform magnetic field through the imaging volume 60. A method for performing the same is also provided.

Abstract: A retainer for retaining a connector to a board is provided. The retainer is positioned between a first carrier board and a second carrier board that is mounted to a circuit board. The retainer body has a middle retainer portion having a hole therethrough. The first retainer side extends from the middle portion. A second retainer side also extends from the middle portion. A first snap is disposed on the first retainer side and a second snap is disposed on the second retainer side. The first snap engages the first carrier board and the second snap engages the second carrier board.

Abstract: An imaging tube (52, 52?) includes a vacuum vessel (96) and an atmospheric-side supply line assembly (104, 104?). The vacuum vessel (96) has an internal vacuum (98). The supply line assembly (104, 104?) has an electromagnetic shield (94, 94?). An insulator (106, 106?) separates the internal vacuum (98) from an external atmosphere (126). A cathode post (92, 92?) resides within the vacuum vessel (96). The cathode post (92, 92?) is in conductive proximity with the electromagnetic shield (94, 94?) and prevents the bending of electrostatic field lines within the imaging tube (52, 52?).

Abstract: A system and method for improved imaging of a patient through the use of low-dose exposure aided positioning is provided. The patient is positioned in the X-ray system and them imaged with a low-dose pre-shot to verify the positioning of the patient. If the patient's positioning is acceptable, the patient is then imaged with a full-dose X-ray exposure. If the patient's positioning is not acceptable, the patient is repositioned and re-imaged with a low-dose pre-shot until the patient's positioning is acceptable. The low-dose pre-shot may take the form of a low-dose X-ray imaging sequence. The present invention thus provides for rapid verification of the proper positioning of the patient in the X-ray system in order to provide for optimal X-ray image quality. Additionally, the X-ray imaging system thus minimizes the additional exposure to X-ray radiation on the part of the patient.

Abstract: A medical diagnostic imaging system includes an X-ray source and X-ray detector, sensors tracking a position of at least one of a surgical instrument and the X-ray detector, and an integrated imaging and navigation workstation. The integrated imaging and navigation workstation includes at least one processor executing fluoroscopic imaging based on an output of the X-ray detector and navigation tracking of positions of a surgical instrument and positions of an X-ray detector with respect to a coordinate system. The integrated imaging and navigation workstation also includes an input receiving surgical instrument tracking signals from the sensors, an input receiving detector tracking signals from the sensors, and a display for displaying fluoroscopic images with a displayed instrument superimposed. In particular, one or more relations of the displayed instrument with respect to the fluoroscopic image (e.g., coordinate location and rotation) corresponds to the relation of the surgical instrument to the patient.

Abstract: A medical imaging system comprises a C-arm unit having an x-ray source for generating x-rays and a receptor for obtaining image exposures from received x-rays. The C-arm unit moves the x-ray source and receptor along an image acquisition path between at least first and second exposure positions. The C-arm unit rotates about a central axis. Source and receptor brackets mount the x-ray source and receptor, respectively, to the C-arm unit. The source and receptor brackets move at least one of the x-ray source and receptor in a radial direction toward and away from the central axis of the C-arm unit to maintain a desired distance between the patient and the x-ray source and receptor. An image processor collects a series of image exposures from the receptor and constructs a three dimensional volumetric data set which is displayed on a display.

Abstract: Methods and apparatus are provided in a diagnostic X-ray system for reducing signal conversion time for a solid-state detector panel of the X-ray system in order to increase frame rate. A measurement of a set of induced signal offsets caused by time varying charge retention associated with the detector panel is performed during a phantom time segment prior to normal signal readout of the detector panel for a current image frame. A set of adjustment values is generated in response to the set of induced signal offsets. Subsets of signal values of the detector panel are read out to a pre-determined signal dynamic range as part of normal signal readout of the detector panel in response to the set of adjustment values, thus generating a set of normalized detector signals.

Abstract: A method and system for of defining, or identifying, regions of interest for exposure management in a digital x-ray imaging system, and especially in the case of multiple consecutive image acquisitions. According to the most basic embodiment of the present invention, simple geometric shapes arranged in a matrix configuration are used to aid an operator in identifying a region of interest for a diagnostic x-ray image. Each region of interest is selectable from a low-dose preshot image and may be corrected, or processed, in order to enhance the results of a subsequent diagnostic image. The processing of the preshot image allows the system to automatically make predictions for the diagnostic image exposure requirements, thereby avoiding unnecessary multiple images.

Abstract: An electron beam tomography (EBT) scanning system comprising an electron source generating an electron beam, a target ring that receives the electron beam and emits an x-ray fan beam upon impingement of the electron beam on the target ring, a pair of detector arrays arranged opposite the target ring, and a collimator arranged concentrically between the target ring and the pair of detector arrays. The collimator has interior and exterior walls concentrically arranged with one another and surrounding a patient examination area. The interior and exterior walls have a first set of apertures aligned to collimate the x-ray fan beam into a first collimated beam having a first width and a second collimated beam having a second width. Each collimated beam may form a single or double tomographic slice. The collimated beams are detected by the pair of detector arrays.

Abstract: Certain embodiments include a system and method for scatter measurement and correction. The method includes performing a calibration scan using a phantom to measure a scatter signal ratio between scatter x-rays impacting a first detector ring and scatter x-rays impacting a second detector ring. The scatter signal ratio is used to determine a scatter scale factor. The method further includes positioning a collimator such that the first detector ring is occluded from a path of primary x-rays generated by a target. The method also includes executing a low exposure scan to obtain x-ray scatter data using the first detector ring and the second detector ring and applying the scatter scale factor to the scatter data to produce scaled scatter data. The method further includes obtaining image data using the first detector ring and/or the said second detector ring and adjusting the image data using the scaled scatter data.

Abstract: A method and apparatus for reducing noise and motion artifacts in pixels of a processed or displayed video image by filtering pixel values of the video image based on a first frame having currently stored (filtered) pixel values and a second frame having recently captured but not yet filtered pixel values. The apparatus includes a spatial filter for computing a motion value of a pixel of interest by averaging difference values of selected pixels surrounding the pixel of interest. Also included is a filter function means for producing an output difference value of the pixel of interest based on the motion value and an adder for adding the output difference value to the first frame filtered pixel value of the pixel of interest. Thus, each pixel of the video image is filtered according to the amount of motion in the video image.

Abstract: The contrast-to-tissue ratio is improved while imaging contrast infused tissue. A subject is infused with contrast medium having microbubbles at a fundamental frequency. First and second transmit pulses are transmitted into the subject. The first and second transmit pulses each comprise first, or basic, and second, or seed, signals. The basic signal has a frequency based on the fundamental frequency and the seed signal has a subharmonic frequency based on the frequency of the basic signal. The first and second transmit pulses are phase inverted with respect to each other. Received echoes from first and second transmit pulses are filtered at a subharmonic or ultraharmonic frequency to remove tissue response and pass microbubble response.

Abstract: A tool is provided for separating a first circuit board and a second circuit board to prevent the damage thereof. The tool includes a piston assembly and a handle. A first blade and second blade are coupled between the handle and the piston assembly. The first blade and the second blade are normally biased outwardly. The handle has a first position and a second position relative to the piston assembly. In the first position the blades are biased outwardly and in the second position the piston assembly biases the blades inwardly to engage the first circuit board.

Abstract: An apparatus, method and system for tracking a medical instrument, as it is moved in an operating space to a patient target site in the space, by constructing a composite, 3-D rendition of at least a part of the operating space based on an algorithm that registers pre-operative 3-D diagnostic scans of the operating space with real-time, stereo x-ray or radiograph images of the operating space. The invention has particular utility in tracking a flexible medical instrument and/or a medical instrument that moves inside the patient's body and is not visible to the surgeon.

Abstract: A method and apparatus is provided for generating and displaying filtered strain rate signals corresponding to tissue structure within a subject in response to complex Doppler signals generated by an ultrasound system. Various combinations of several processing techniques are employed including filtering out high strain rate signals due to reverberation and other sources of noise, complex autocorrelation, velocity signal estimation, real strain rate signal estimation, complex strain correlation signal estimation, complex signal averaging, and real signal averaging. Color strain rate imaging is provided using the techniques such that the color images have reduced noise and improved image quality.

Abstract: An X-ray tube subsystem including an X-ray tube and a grid voltage supply that reduces high voltage breakdown events. The X-ray tube provides a grid bias connection, a filament bias connection, and an anode bias connection. The grid voltage supply is connected to the grid bias connection and is adapted to produce an ion collection voltage substantially less than an electron beam focus voltage.