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: 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: 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: 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: 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.

Abstract: The present invention provides an electromagnetic tracking system that includes a field generator and a field sensor arranged to generate and detect, respectively, an electromagnetic field. Both the transmitter and receiver coils are connected to signal conditioning and processing circuitry to provide outputs indicative of the coil signals. A processor operates on the signals to determine the coordinates of the sensing assembly relative to the generator assembly. The signal processor produces ratiometric outputs, and applies a mutual inductance model to solve for position/orientation coordinates. In some embodiments, a disturber in the form of a conductive ring or a sheath is disposed about an interfering piece of equipment to moderate and standardize disturbances due to eddy currents.

Abstract: A method for integrating a picture archiving and communication system (“PACS”) and a voice dictating or speech recognition system (collectively “voice dictation system”) is provided. The method includes logging in to a PACS. The method also includes automatically logging in to a voice dictation system responsive to the logging in step and opening an image file in the PACS. The integration method further includes automatically creating a dictation file associated with the image file in the voice dictation system responsive to at least one of the logging in step, the automatic logging in step or the opening step. The method may optionally include sending a predetermined identifier to the dictation file to associate the image file with the dictation file. The method may additionally optionally include performing the automatic logging in step responsive to the PACS being in a dictation mode.

Abstract: A transesophageal ultrasound probe for imaging internal structures via an imaging element located on the distal end of a rotating endoscope shaft. The probe includes a rotating endoscope having an imaging element mounted on the distal end of the rotating endoscope shaft. The probe also includes a control handle for controlling the imaging controls and a rotation tube that extends through the rotating endoscope shaft and into the control handle. The rotating shaft rotates relative to, and independently of, the control handle. Preferably, the rotating shaft is rotated via a rotation control wheel. The rotation control wheel is fastened or bonded to the rotating tube so that manual rotation of the control wheel causes the rotation tube to rotate, and therefore, the rotating shaft to rotate. Because the rotating endoscope shaft rotates, an imaging element located on, or within, the rotating shaft also rotates.

Abstract: A method of automatic registration includes forming an image of a body part including a representation of markers fixed in a known position in space relative to a reference mount, positioning a sensing unit in a known position in space relative to the reference mount, and automatically registering the sensing unit in space relative to the formed image based on the location of the markers in the formed image, the known location of the markers relative to the reference mount, and the known location of the sensing unit relative to the reference mount.

Abstract: A method and apparatus for tissue dependent filtering for digital image magnification includes using bilinear interpolation and digital convolution filters to approximate bicubic interpolation for digital image magnification. A library of set s of representative images may be created for particular anatomies and particular imaging modalities. Two-dimensional convolution filter coefficients may be estimated using a set of representative images chosen for a particular anatomy. The two-dimensional convolution filter coefficients may be employed to form a two-dimensional convolution filter to be used with bilinear interpolation to magnify a digital image.

Abstract: A scanning electron beam computed tomographic system eliminates axial offset between target and detector by disposing the target, collimator, and detector such that active portions of the target and detector are always diametrically opposite each other. This result is achieved by providing a helical target, collimator, and detector, or by providing planar target, collimator, and detector components that are inclined relative to the vertical axis such that active portions of the target and detector are always diametrically opposite each other. Either configuration eliminates cone beam error and the necessity to correct for same. Further, the system can provide multi-slice scanning of an object that is in constant motion at a critical velocity, without having to interpolate data. Conventional helical scanning may still be undertaken. Detector elements can be disposed axially to improve signal/noise ratio and to produce a cone beam cancellation effect.

Abstract: An x-ray detector is provided to acquire an image. The x-ray detector comprises detector elements that store a charge representative of an x-ray level. The detector elements are arranged in rows and columns. Scan lines are arranged in rows or columns and connect to the detector elements. First and second sets of sensing circuits read the charge from the detector elements. A first set of data lines connects to the first set of sensing circuits and a second set of data lines connects to the second set of sensing circuits. At least one of the data lines from the first set of data lines is interspersed with the second set of data lines.

Abstract: A computer assisted surgery system is described for assisting a surgeon in aligning a drill with the interlocking holes of an implanted intramedullary (IM) rod used for fixation of long bone fractures. With the IM rod inserted, a localizing device measures the pose of a tracked adapter attached to the rod's exposed end. Approximate AP and lateral fluoroscopic x-ray images are acquired of the end of the rod with the interlocking holes. Image processing algorithms determine the actual position of the rod and calculate an adjustment to the pose of the tracked adapter and IM rod. Using the adjusted pose information, the system displays, in three roughly orthogonal views, a representation of the drill trajectory relative to the images of the IM rod and relative to a graphic representation of the IM rod.

Abstract: An image guided surgery system to enable a surgeon to move a surgical tool into a desired position relative to a body part is provided. The system works by accurately superimposing representations of the tool being used in the surgical field over images of the body part such that real-time tool position feedback is provided to the surgeon. The system uses a fluoroscopic x-ray device to generate two-dimensional body part images, a localizing device to determine the poses of surgical tools and the x-ray device, mathematical modeling of the imaging chain of the x-ray device, and a display for displaying the images of the body part superimposed with representations of the surgical tools. A digital flat-panel x-ray imager permits fluoroscopic x-ray device to be used in any orientation without being affected by distortions due to local magnetic fields.