Abstract: A Compton Deconvolution Camera (CDC) comprises multiple detection layers, position sensing logic to determine positions of events in each detection layer, a coincidence detector to detect pairs of coincident events resulting from Compton scattering, and processing logic. For each of multiple subsets of one of the detection layers, the processing logic associates data representing detected events with a distribution of corresponding events in another detection layer. The processing logic applies a deconvolution function to localize probable source locations of incident photons, computes probable Compton scattering angles for event pairs, and uses the probable source locations to reconstruct an image. Each of the detection layers may comprise an array of solid-state ionization detectors, or a scintillator and an array of solid-state photodetectors.

Abstract: An ultrasonic transducer, method, and system are disclosed for performing ultrasonic harmonic imaging in a medium or a living body. The ultrasonic transducer consists of a linear array of alternating long and short elements. A first set of transducer elements is for transmitting and receiving at a fundamental frequency, and a second set of transducer elements is for receiving second harmonic or subharmonic echoes, each set operating at their respective center frequencies. This dual-frequency ultrasonic transducer is coupled to an ultrasound system wherein transmit beamforming is done at the fundamental frequency, and receive beamforming is done at the second harmonic or subharmonic frequency. When receive beamforming at the fundamental frequency is added, the method enables parallel fundamental, harmonic, compound, and difference imaging.

Abstract: An ultrasonic transducer, method, and system are disclosed for performing ultrasonic harmonic imaging in a medium or a living body. The ultrasonic transducer consists of a linear array of alternating long and short elements. A first set of transducer elements is for transmitting and receiving at a fundamental frequency, and a second set of transducer elements is for receiving second harmonic or subharmonic echoes, each set operating at their respective center frequencies. This dual-frequency ultrasonic transducer is coupled to an ultrasound system wherein transmit beamforming is done at the fundamental frequency, and receive beamforming is done at the second harmonic or subharmonic frequency. When receive beamforming at the fundamental frequency is added, the method enables parallel fundamental, harmonic, compound, and difference imaging.

Abstract: A Compton Deconvolution Camera (CDC) comprises multiple detection layers, position sensing logic to determine positions of events in each detection layer, a coincidence detector to detect pairs of coincident events resulting from Compton scattering, and processing logic. For each of multiple subsets of one of the detection layers, the processing logic associates data representing detected events with a distribution of corresponding events in another detection layer. The processing logic applies a deconvolution function to localize probable source locations of incident photons, computes probable Compton scattering angles for event pairs, and uses the probable source locations to reconstruct an image. Each of the detection layers may comprise an array of solid-state ionization detectors, or a scintillator and an array of solid-state photodetectors.

Abstract: Methods and apparatuses for providing simultaneous viewing of an instrument in two ultrasound imaging planes. An ultrasound imaging probe is provided which can generate at least two ultrasound imaging planes. In one embodiment, the two imaging planes are not parallel (i.e., the planes intersect). An instrument path is positioned with respect to the planes such that an instrument may be simultaneously viewed in both imaging planes. In one embodiment, the instrument path is provided at an intersection that, at least partially, defines the intersection of the two imaging planes.

Abstract: A forward-scanning ultrasound catheter probe. An ultrasound catheter probe includes a forward-scanning transducer positioned at the tip of the probe. As such, the forward-scanning transducer may provide images of structures that may lie ahead of the tip of the probe. Furthermore, the forward-scanning transducer is repositioned by a drive mechanism coupled to the front-scanning transducer to provide a sector scan. In one embodiment, a bimorph piezoelectric drive is utilized to sweep the forward-scanning transducer across an arc to provide an imaging area associated with a sector scan.

Abstract: A system is disclosed for measuring volume flow through vessel. A longitudinal area of a vessel in a body is scanned using a color Doppler imaging method, such that an imaging plane is formed approximately through the center of said vessel. A number of color pixels in a scanned cross-section of the vessel in which volume flow is detected are counted and tabulated. From this number of pixels, an observed cross-sectional area of the vessel is determined. Frequency shift information for each of the counted pixels is determined and these frequency shifts are spatially averaged. The instantaneous volume flow through the vessel is then computed from the cross-sectional area and frequency shift information. The volume flow for several different samples is computed. The instantaneous volume flows from each color Doppler imaging frame are temporally averaged over one or more integral cardiac cycles to compute a temporally-averaged volume flow.

Abstract: A system is disclosed for performing vibrational resonance ultrasonic Doppler spectrometry to produce characteristic vibrational resonance spectra of soft structures in compressible media or soft tissues in a living body. A system is further disclosed for vibrational resonance ultrasonic Doppler imaging of the spatial distribution of vibrational resonance properties. An audio-frequency source externally applies a sequence of vibrational frequencies into a medium or body. Ultrasonic pulsed Doppler beams are focused at various locations within a region of interest, and the received Doppler signals are used to estimate the amplitude of the vibrational resonance response at each location. A vibrational resonance spectrum is computed from received Doppler amplitudes at each vibrational frequency and graphically displayed.

Abstract: A method and apparatus for determining resistance and pulsatility indices of a flow of material, such as the flow of blood in the human body. This may be implemented, for example, in a color flow module in an ultrasonic imaging system for display of the pulsatility or resistance index in two dimensions and in different colors to allow discrimination between veins and arteries and detection of pathologic elevation of vascular resistance in a clinical survey mode of the system. The resistance index is determined from the ratio of a unipolar variation estimate of a velocity of the flow material divided by a peak velocity. The variation estimate may be one of the following: a difference between a peak velocity of the flow of material and a second minimum (if unipolar) or negative (if bipolar) velocity of the flow of material, a standard deviation .rho.

Abstract: A method and apparatus for generating three-dimensional (3D) images of flow structures and their flow lumen using ultrasound techniques. According to one aspect of the invention, a border between a flow region and a non-flow region is used to render a three-dimensional image of the flow lumen of the flow structure. The images may be viewed in real-time and/or stored on a machine-readable medium. In one embodiment, the three-dimensional images may be manipulated in a number of viewing directions/angles/distances/positions/styles. In one embodiment, a flow lumen may be displayed using a virtual angioscopic view.

Abstract: A system is disclosed for performing vibrational Doppler ultrasonic imaging. A vibrational wave of a first frequency is introduced into an area of a subject to be scanned. An ultrasound signal is simultaneously introduced into the area. The vibrational wave is of a sufficient frequency and amplitude to induce palpable vibrations in the tissue medium of the area being scanned. An ultrasonic Doppler imaging system detects these tissue vibrations and processes the resulting scanned data for display on a display device.

Abstract: A system is disclosed for performing ultrasonic color Doppler imaging to produce absolute velocity and flow direction information for complex media. Ultrasonic color Doppler beams are steered at two different angles and samples are taken at the points of intersection between the steered beams. The duplex color Doppler sample volumes are two overlapping sample volumes interrogated from different angles. Frequency-shift information provided by the color Doppler sample volumes are used to compute the absolute mean velocity and direction of motion of acoustic reflectors within the sample volumes. Velocity and direction data are computed for a two-dimensional array of duplex color Doppler sample volumes and mapped into a color scale to provide a spatial distribution of the velocity or direction of flow or motion of acoustic reflectors.