Abstract: A combined emission-transmission imaging apparatus, the apparatus comprising oppositely facing first and second photon detector segments disposed on opposite sides of an imaging area and defining the imaging area there between and a radiation source disposed adjacent and outside the imaging area and adjacent at least one of the detector segments, the source generating a fan beam of radiation that emanates from a focal point and juxtaposed such that the fan beam is directed along a trajectory through the imaging area and toward the other of the detector segments, wherein the segments collect both emission and transmission radiation.

Abstract: An apparatus is provided for aligning a laser beam with a hidden target. In particular, a coupling is rotated which rotates a laser diode and simultaneously translates the diode to produce a spiral shaped laser beam path. The coupling is continuously rotated until it is determined that the beam has become aligned with the target.

Abstract: Two independently articulated arms supporting an x-ray tube and x-ray detector, respectively, are mounted offset to the patient and controlled to simulate a wide variety of conventional x-ray positioners. The articulated arms provide for at least two axes of independent motion. An axis controller sends movement signals to each axis, and receives position signals from each axis to coordinate movement of the axes of the articulated arms according to a contained program. A network interface communicates with the axis controller for receiving at least a portion of the program over a network.

Abstract: An x-ray positioner is provided having two independently articulated arms supporting an x-ray tube and x-ray detector, respectively, that are mounted offset to the patient and controlled to track a bolus travelling through a patient. A controller is provided with feedback information regarding the bolus to determine the rate of travel, and to produce motion signals to the arms to automatically track the movement of the bolus.

Abstract: A method and apparatus for calibrating PET PMTs, the method including, during a commissioning process, determining gain factors for each crystal in a detector unit that cause the peak energy level in a crystal energy spectrum to be equal to a target value and, during a calibration process, generating energy spectrums for each crystal in the unit, combining the gain factors and crystal spectrums to generate shifted crystal spectrums, combining the shifted spectrums to generate a unit spectrum, identifying the peak unit spectrum energy level and comparing the peak unit level to the target value to generate PMT adjustment levels.

Abstract: An imaging system coupled to a network, the network coupling imaging devices of at least first and second different imaging modalities, each modality including functions which are common to each of the first and second modalities, includes an imaging device, a network coupling the imaging device to a remote facility, an interface associated with the imaging device, and a pointing device for moving a pointer icon about the display and for selecting displayed icons. The network provides the imaging device with remote services from the remote facility. The interface includes a display and a programmed data processor for providing a uniform interface image on the display despite the specific modality.

Abstract: Two independently articulated arms supporting an x-ray tube and x-ray detector, respectively, are mounted offset to the patient and controlled to simulate a wide variety of conventional x-ray positioners. The arms are at least partially defined by a plurality of links that are connected at joints having independent axes of motion. The number of links, and corresponding degrees of freedom for the arms may be predetermined based on the end user application for the positioner.

Abstract: A timing circuit for implementation in a medical imaging system such as a PET scanner, and a method of ascribing times to events in such systems, is disclosed. In one embodiment, the timing circuit includes a quadrature clock, four counter elements, four status circuits, and four output registers. The clock provides four differently-phased clock signals at a single frequency, and the four counter elements respectively receive the clock signals and provide count signals. The four status circuits all receive an event detection signal and further receive the respective clock signals, and in response provide four status signals indicative of whether the event detection signal has experienced a status change. The four output registers receive the respective clock, status and count signals, and in response provide four output signals that are collectively indicative of a time at which the event detection signal experiences the status change.

Abstract: A method of processing an image data set of a 3D PET scanner to correct for scattered coincidence events, as well as a 3D PET scanner, are disclosed. The method of processing the image data set includes providing an image data set including a first plurality of data subsets respectively corresponding to a plurality of native slices. The method additionally includes axially downsampling the first plurality of data subsets to generate a second plurality of data subsets respectively corresponding to a plurality of super-slices. The method further includes calculating scatter in the second plurality of data subsets by way of a model-based scatter correction algorithm.

Abstract: An integrated x-ray imaging detector assembly is provided for use in an x-ray imaging system. An x-ray detector module is supported by a frame and receives a beam of x-rays emitted from an x-ray source and passed through a target along a detector axis. The x-ray detector is further operable to produce electrical signals in response to the received beam of x-rays. A display terminal is supported by the frame and disposed behind the detector module with respect to the direction of x-ray beam travel. The display terminal is configured to receive the electrical signals and produce an output image corresponding to the electrical signals.

Abstract: Two independently articulated arms, each having at least two independent axes of motion, support an X-ray tube and X-ray detector, respectively, are mounted offset to the patient and controlled to simulate a wide variety of conventional X-ray positioners. The two arms are each supported at one end by a common base wherein the common base provides at least one common axis of motion for both the first and second articulated arms. Further, an axis controller sends movement signals to the common axis and independent axes and receives position signals from the common axis and independent axes to coordinate movement of the first and second arms according to a predefined program.

Abstract: A method and apparatus for reducing trigger jitter from a CT system position encoder including the steps, for each trigger pair in the encoder signal, identifying the integer portion of average period corresponding to N preceding trigger pairs, identifying a modulus-N residual corresponding to the N preceding trigger pairs as a lag value, adding the lag value to a lag count, determining when the lag count exceeds N and, where the lag count exceeds N, incrementing the integer portion by one, identifying a modulus-N residual corresponding to the lag count, setting the lag count equal to the residual corresponding to the lag count and generating a final binary trigger signal corresponding to the integer portion.

Abstract: Calibration data is acquired during a prescan in an MRI system from each local coil in a coil array. The calibration data is used to calculate a sensitivity matrix S which is employed in a SENSE technique to reconstruct an MR image acquired with the same local coils.

Abstract: A digital image processing method includes the steps of acquiring (60) pixel data which defines a digital image (36), identifying (66) structural regions (48) within the digital image, resulting in a structure mask showing the structural regions and non-structural regions (50), enhancement filtering (68-76) the digital image using the structure mask, and correcting (78) for intensity non-uniformities in the digital image, resulting in an enhanced, corrected digital image. An apparatus for carrying out the method includes a signal processing circuit configured to receive signals representing the internal features and to perform the steps (60-78) of the method.

Abstract: An x-ray imaging system is presenting having two independently articulated arms supporting an x-ray tube and x-ray detector, respectively. The detector is included in a detector assembly that further includes a display and user interface for controlling the arms. The detector assembly further includes at least one lead shield that is extendable to protect an operator stationed at the display during use.

Abstract: A method and apparatus is disclosed for processing, in a magnetic resonance imaging system, a magnetic resonance signal including transient spike noise. The method includes receiving an initial signal related to the magnetic resonance signal, the initial signal including a carrier signal modulated by a modulation signal and further including a transient spike noise component. The method further includes determining an envelope signal indicative of an envelope of the initial signal, such that the envelope is indicative of the modulation signal and further indicative of the transient spike noise component. The method additionally includes filtering the envelope signal by way of a high-pass filter to remove information relating to the modulation signal from the envelope signal and to produce a filtered envelope signal indicative of the transient spike noise component.

Abstract: A method and apparatus for generating an optimally registered working set of two-dimensional CT images in a gated CT system, the method including, where an acquisition period is divided into sequential acquisition phases, obtaining CT image data for separate phase ranges during each acquisition phase, generating phase image sets including 2D images for each phase range and selecting one phase range image set corresponding to each acquisition phase to generate a working image set where the selected phase range image sets are optimally aligned.

Abstract: A method and apparatus for performing image reconstruction using data obtained by an N beam helical scan, the method including generating projection data arrays for each of the N row in a CT detector, weighting the data arrays using a unique weighting function that is applicable to detectors having many different numbers of rows N to generate helical weighted arrays for each row, weighting the helical weighted arrays by applying a conjugate weighting function to generate conjugate arrays for each detector row and then combining the conjugate weighted arrays, filtering and back-projecting to generate a slice image.

Abstract: Monitor signals are acquired in an interleaved manner during a scan with an MRI system. Frequency changes caused by variations in the polarizing field B0 are measured using the monitor signals, and these measured frequency changes are employed to compensate image data acquired during the scan. Electrical currents are produced in a set of shim coils that shim the polarizing field B0 in the immediate vicinity proximal to the monitor coil.

Abstract: A method and apparatus for performing image reconstruction using data obtained by an N beam helical scan, the method including generating projection data arrays for each of the N rows in a CT detector, weighting the data arrays using a unique weighting function that including different weighting functions for a first detector row, a last detector row and the middle detector rows between the first and last detector rows thereby generating helical weighted arrays for each row, applying a half scan weight to each helical weighted array and using the half scan weighted arrays to generate a slice image.