Abstract: A method and apparatus for generating a diagnostically usable three-dimensional image data set is disclosed. The ultrasonic images generated from an ultrasonic apparatus are supplied to an image processing system which uses a position sensor system to determine the spatial location of the ultrasonic image in each dimension. The raw data are transformed into three-dimensional data set having numerous voxels with associated image or gray values, the image or gray values being formed for each voxel according to a preassigned algorithm, to wit from the image or gray values of those image points which are closest in each instance to the current voxel in the unit images or their image planes and whose distance from the current voxel does not exceed a preassigned maximum allowable distance.

Abstract: An ultrasound method and system are provided for producing three dimensional images. During an imaging session, a transducer, in response to a transmit beamformer, transmits ultrasonic energy at a first frequency band into a subject. The subject may be kept free of added ultrasound contrast agent throughout the entire imaging session. A receive beamformer receives ultrasonic echo information associated with the transmitted ultrasonic energy. Information signals associated with a second frequency band, such as a harmonic frequency band, are obtained from the echo information. A three-dimensional reconstruction is formed or a volume quantity is calculated in response to the information signals. The transmission of ultrasonic energy may also include energy focused along an elongated high power region or a line focus.

Abstract: A three dimensional M-mode imaging system and techniques are described for acquiring and forming three dimensional ultrasonic M-mode images from ultrasonic data acquired over time from a stationary scanhead. The resultant images exhibit two spatial dimensions and one temporal dimension.

Abstract: An image processing apparatus can display a tomographic image of an object in a three-dimensional region and a three-dimensional or stereoscopic image, such as a three-dimensional surface image of the object or a three-dimensional transparent image thereof, simultaneously on a screen. A sectional plane from which the tomographic image is produced is freely designated on the three-dimensional image displayed on the screen. The sectional plane can be indicated on the displayed three-dimensional image by a cursor line. Further, a data processing range along the ultrasound beam direction can be determined on the displayed tomographic image, in which the three-dimensional image is produced from the echo data obtained from the data processing range. Such a data processing range can also be indicated on the displayed tomographic image by means of cursor lines.

Abstract: A method and an apparatus for three-dimensional imaging of ultrasound data by combining projections of intensity data with projections of velocity or power data from a volume of interest. The apparatus is an ultrasound scanner which collects B-mode or color flow images in a cine memory, i.e., for a multiplicity of slices. The data from a respective region of interest for each slice is sent to a master controller, such data forming a volume of interest. The master controller performs an algorithm that projects the data in the volume of interest on a plurality of rotated image planes using a ray-casting technique. The combined intensity and velocity or power data for each projection is stored in a separate frame in the cine memory. These reconstructed frames are then displayed selectively by the system operator.

Abstract: An ultrasonic three-dimensional image formation apparatus forms ultrasonic three-dimensional images from ultrasonic echoes using a cross array including two linear phased arrays. Thus, an ultrasonic three-dimensional image can be obtained using a small amount of data to thereby enable a real-time three-dimensional image formation.

Abstract: A 3D field of view ultrasound image volume is derived from correlated frames of ultrasound image data. An operator manually translates an ultrasound probe across a patient target area. Frames of sensed echo signals are processed to detect probe motion using beam data registration and correlation techniques. Motion is detected by correlating the frames for probe translation among as many as 6 degrees of freedom. Image registration then is performed for correlated portions to accumulate a large ultrasound image. Such image encompasses an area larger than a single field of view image frame for the given manually-scanned transducer probe.

Abstract: A method and an apparatus for improving the segmentation of a three-dimensional B-mode image by limiting the volume of pixel intensity data projected onto the imaging planes. If the volume of interest contains moving ultrasound scatterers, e.g., blood flowing in an artery or vein, the Doppler shift present in the ultrasound reflected from the flowing blood can be detected and then used to limit the amount of pixel data which is projected. The velocity or power data is used to identify those intensity values to be projected onto the imaging plane. This is accomplished by locating a reference data volume of pixels for which the velocity or power value is non-zero and then defining a source data volume which is essentially a function of that reference data volume. The reference data volume comprises pixels acquired from echo return signals reflected by the moving ultrasound scatterers.

Abstract: A method and an apparatus for mitigating aliasing when imaging moving fluid or tissue using velocity Doppler shift data. To eliminate the effects of slight aliasing in the velocity mode, symmetrical (or non-directional) velocity/color maps are used to map positive and negative velocity data of the same magnitude to the same color and same display intensity. If the pulse repetition frequency is adjusted so that only subtle aliasing is present, an optimal frame averaging of the data can be achieved by removing the sign of the velocity data either before or during frame averaging.

Abstract: A system and method for 3-D ultrasound image registration and 3-D motion estimation. A calibrated 3-D speckle function is first pre-determined for the transducer and the tissue to be scanned. A series of image frames are identified and grouped into 3-D big and small blocks. Blocks representing speckle are identified and then, a full width half maximum value sum-absolute-difference technique is used to obtain an out-of-plane motion estimation based on decorrelation characteristics throughout the volume. For in-plane motion estimation, cross-correlation characteristics between pairs of frames are compared and, using a minimum sum absolute value technique, an estimate of in-plane motion is obtained. Fuzzy logic techniques are then used to obtain more accurate estimates. Finally, the out-of-plane motion estimate is updated based on decorrelation characteristics of the speckle frames used for the in-plane determination using a full width half maximum value technique.

Abstract: An ultrasonic transducer acquires a series of ultrasound tomograms as it continuously rotates through a range of angles. When positioned in a left ventricular long axis view, serial sectional slices are acquired within 6 seconds from which a 3D image is reconstructed. The boundary of the left ventricle is identified in this 3D image using a reference database produced by a learning process that captures expert knowledge of left ventricle cavity shapes.

Abstract: A method and an apparatus for three-dimensional imaging of ultrasound data by constructing projections of data from a volume of interest. An ultrasound scanner collects B-mode or color flow images in a cine memory, i.e., for a multiplicity of slices. A multi-row transducer array having a uniform elevation beamwidth is used to provide reduced slice thickness. The data from a respective region of interest for each of a multiplicity of stored slices is sent to a master controller, such data forming a volume of interest. The master controller performs an algorithm that projects the data in the volume of interest onto a plurality of rotated image planes using a ray-casting technique. The data for each projection is stored in a separate frame in the cine memory. These reconstructed frames are then displayed selectively by the system operator. Segmentation of three-dimensional projection images is enhanced by decreasing the thickness and increasing the resolution (i.e.

Abstract: A medical diagnostic ultrasound system is described in which ultrasonic B mode tissue information and Doppler flow information is acquired from a volumetric region of the body and processed in an interleaved sequence to render a three dimensional image. The three dimensional rendering processes the B mode and Doppler flow information to give priority to tissue information, flow information, or a blend of the two.

Abstract: Complex equipment operated by a plurality of computerized task functions is coupled to a host processor which controls operation of a plurality of task functions performed by the equipment. Included in the equipment are a plurality of client processors, a communications network coupling the host processor to the client processors, and a plurality of programs providing respective task interfaces for running selected task functions of the equipment on any of the client processors as remote processes. Each task interface program includes a library of communications handlers and a designated task interface. When the complex equipment comprises an ultrasound imager system, the task functions of shaping a transmit waveform and shading the transducer reception parameters are performed through preferred embodiments of such task interfaces. A voice input task function may also be run as a remote process coupled to the imager host through the network interface.

Abstract: An ultrasonic diagnostic imaging system is provided for measuring the volume of a chamber of the heart or other organ or vessel. An ultrasonic transducer probe is used to scan the chamber with a plurality of spatially distinct scan planes. The pixels of the chamber volume of each scan plane are aggregated to provide a measure of the volume. In a preferred embodiment the chamber volume pixels are developed from Doppler signals from the fluid within the chamber, and are related to voxels within the chamber by weighting pixels in the scan planes in accordance with the voxel sampling afforded by the inter-plane separation.

Abstract: A three-dimensional ultrasound imaging system includes an ultrasound probe to direct ultrasound waves to and to receive reflected ultrasound waves from a target volume of a subject under examination. The ultrasound probe is swept over the target volume along a linear scanning path and the reflected ultrasound waves are conveyed to a computer wherein successive two-dimensional images of the target volume are digitized. The digitized two-dimensional images can be used to generate a three-dimensional image with virtually no delay. A user interface allows a user to manipulate the displayed image. Specifically, the entire displayed image may be rotated about an arbitrary axis, a surface of the displayed image may be translated to provide different cross-sectional views of the image and a selected surface of the displayed image may be rotated about an arbitrary axis. All of these manipulations can be achieved via a single graphical input device such as a mouse connected to the computer.

Abstract: A method and an apparatus for three-dimensional imaging of ultrasound data by constructing projections of data from a volume of interest. An ultrasound scanner collects B-mode or color flow images in a cine memory, i.e., for a multiplicity of slices. A multi-row transducer array having a uniform elevation beamwidth is used to provide reduced slice thickness. In particular, the multi-row transducer array has a central row made up of elements having an area smaller than the combined area of the paired elements of two outermost rows The data from a respective region of interest for each of a multiplicity of stored slices is sent to a master controller, such data forming a volume of interest. The master controller performs an algorithm that projects the data in the volume of interest onto a plurality of rotated image planes using a ray-casting technique. The data for each projection is stored in a separate frame in the cine memory. These reconstructed frames are then displayed selectively by the system operator.

Abstract: A method and apparatus for ultrasonically producing 3-dimensional images in real time, wherein a device transmits an ultrasonic wave toward a solid bearing angle obtained by dividing into multiple portions a solid bearing angle subtended by a sonic field to be examined, and receives echoes therefrom, with the transmitted waves being sequential and the received echoes being concurrent multiple waves from each small solid angle, and a device for producing the 3-dimensional images by range gating the received echo signals in the depth direction of the sonic field being examined and then producing direct vision images in the direction of the transmitted ultrasonic waves based on the echo signals, wherein the range gated signals are quadrature detected in one embodiment and/or are subjected to 2-dimensional Fourier transformation in another embodiment.

Abstract: An ultrasonic diagnostic apparatus either for displaying three-dimensional ultrasonic images allowing an operator to become aware of the distance of a target object from an ultrasonic probe, or for displaying practical three-dimensional ultrasonic images while being simply structured and taking a short time to perform necessary operations.

Abstract: A stereoscopic ultrasonic imaging apparatus for displaying in a short time an ultrasonic image giving a sense of perspective. The apparatus comprises: two two-dimensional ultrasonic receiving element arrays arranged a predetermined distance apart; an orthoscopic image generation unit for generating a plurality of orthoscopic images of an observed surface perpendicularly intersecting an ultrasonic beam applied, the orthoscopic images having a predetermined parallax therebetween and generated on the basis of received ultrasonic data obtained by the element arrays; and a stereoscopic display unit for displaying stereoscopically the orthoscopic images generated by the orthoscopic image generation unit.

Abstract: Data provided by sound rays acquired by performing spiral scanning using ultrasonic waves is converted into image data through polar coordinate transformation. Data of slices is displayed and scanned along each scanning line from a start point of scanning lines to a far point. A point closest to the start point of scanning lines is extracted from each run of consecutive points at which luminance values exceed a threshold while a run of points having an unacceptable length is eliminated as a noise. Thus, the surface of an object is extracted.

Abstract: A system for displaying a 2-D ultrasound image in a 3-D viewing environment. Within the same 3-D viewing environment, various surgical instruments can be tracked and displayed, thus correlating 3-D virtual surgery with ultrasound imaging for verification. A detachable housing (220) containing position transducers (222) is attached to a conventional 2-D ultrasound imaging head (200) to provide position data of an imaging plane generated by an image transducer (204).

Abstract: The present invention provides a system and method for visualizing internal images of an anatomical body. Internal images of the body are acquired by an ultrasound imaging transducer. The position and orientation of the ultrasound imaging transducer is tracked in a frame of reference by a spatial determinator. The position of the images in the frame of reference is determined by calibrating the ultrasound imaging transducer to produce a vector position of the images with respect to a fixed point on the transducer. This vector position can then be added to the position and orientation of the fixed point of the transducer in the frame of reference determined by the spatial determinator. The position and orientation of a medical instrument used on the patient are also tracked in the frame of reference by spatial determinators. The position and orientation of the instrument is mapped onto the position and orientation of the images.

Abstract: This invention employs an ultrasound apparatus with a phased transducer having transmit and receive array systems to form an electronically scanned ultrasonic "pencil" beam (25) from crossed flat acoustic beams. The flat transmit beams and flat receive apertures are shaped by the arrays with size of individual elements on the order of the wavelength of a generated carrier frequency in a human body. The separation of array functions in the transmission and reception modes reducess the side lobe level and improves the noise performance. A fast method of acquisition of two dimensional images is described. This method uses a property of a dynamic focused and scanned flat acoustic beam together with the ability to shape flat synthetic receive apertures from digitized and memorized amplitude information.

Abstract: A 3D image is generated in real-time on an ultrasound medical imaging system which performs acquisition, volume reconstruction, and image visualization tasks using multiple processors. The acquisition task includes deriving position and orientation indicators for each gathered image frame. Volume reconstruction includes defining a reference coordinate system within which each image frame in a sequence of image frames is registered. The reference coordinate system is the coordinate system for a 3D volume encompassing the image planes to be used in the 3D image. The first image frame is used to define the reference coordinate system. As each image plane is registered, a 2D projection of the incremental volume is displayed. A shear-warp factorization process is used to derive a 2D projection for a rotated volume. A viewing transformation matrix is factorized into a 3D shear which is parallel to slices of the reference volume. A 2D warp then is implemented to produce the projection of the rotated volume.

Abstract: An image registration based method and a corresponding apparatus are provided for creating composite, panoramic images, in which consecutive ultrasonic image frames are correlated in order to derive transducer motion information. The individual images can be divided into several smaller sub-image regions and a fast and robust image motion detection algorithm is used to measure the sub-image motion and then to determine an initial estimation of the local motion vectors. The initial estimation is combined with two measurement parameters by use of a fuzzy logic technique to derive a final estimation of the local motion vectors. The final local motion vectors are then used to estimate global image motion. Compound images are then diplayed based on the derived global image motion. The speed of motion of the transducer is also estimated and a "speedometer" is displayed to help the user move the transducer within efficient speed ranges.

Abstract: A method of displaying an ultrasonic image and an apparatus for ultrasonic diagnosis of this invention are capable of displaying C-mode ultrasonic image without the need of a probe moving mechanism and a probe movement controller. The linear images produced from the B-mode image data sampled along the scanning planes P(y1,t1).about.P(y5,t5) and in the constant depth z1 are displayed by being arrayed in the order of sampling times t of each linear image.

Abstract: A method and an apparatus for three-dimensional imaging of ultrasound data by reducing speckle artifact data before the acquired data from a volume of interest is projected onto an image plane. An ultrasound scanner collects B-mode or color flow mode images in a cine memory, i.e., for a multiplicity of slices. The data from a respective region of interest for each slice is sent to a master controller, such data forming a volume of interest. The master controller performs an algorithm that iteratively projects the pixel data in the volume of interest onto a plurality of rotated image planes using a ray-casting technique. Prior to projection, the master controller smooths the speckle contained in the pixel data filtering using a convolution filter having a nine-point kernel.

Abstract: In a method of displaying a biplane image in real time in an ultrasonic diagnosing apparatus, ultrasonic waves are transmitted from a biplane probe to a portion of a sample to be diagnosed to scan two sectional planes that intersect orthogonally at an axis of intersection. Echo signals reflected from the sample portion are received by the probe. A tomographic image of each of the two orthogonal sectional planes is displayed on a display unit, each of the two displayed tomographic images being divided into two tomographic image planes along a line of intersection representing the axis of intersection of the two sectional planes. An image for inputting a visual field direction is also displayed on the display unit. Using an input device, a parameter indicating a chosen visual field direction is input to the image for inputting the visual field direction. Affine transformation parameters of the two displayed tomographic images are operated using the parameter of the chosen visual field direction.

Abstract: An interactive scanning device or system having one or more single or multi-dimensional scanners, an input device, an image processor, and a communication interface, for scanning an object or surface and interactively displaying and manipulating a threedimensional image of the object or surface from the geometrical dimensions of the object or topology of the surface captured during scanning. The communication interface enables the geometrical dimensions of the object, the topology of the surface, or the image of the object, to be transmitted over a wire or wireless communication medium to an end user station having an interactive scanning device or a computer station, or both, for initial or further display and manipulation. A further embodiment of the present invention incorporates a photosensitive or photographic recording device to capture an optical image of the object or surface to superimpose with the scanned image.

Abstract: The present invention provides for x-ray imaging and ultrasound imaging of a body region of interest in a spatially correlatable manner. The resultant x-ray and ultrasound images may be combinatively employed to provide three-dimensional information regarding a location of interest within the body, and is particularly apt for use in the analysis/biopsy of potential lesions and suspicious masses in a female breast. The invention provides for direct body contact by an ultrasound imaging head, as well as targeted ultrasound imaging of a selected portion of the region from which x-ray images are obtained.

Abstract: A catheter system and method of use thereof to obtain accurate three-dimensional reconstruction of a body vessel. The method employs X-ray angiography (ANG) in combination with intravascular ultrasound (IVUS) to overcome limitations existing in present three-dimensional reconstruction techniques using a method termed ANGUS. The IVUS data represent a cylindrical stack of cross-sections. A 3-D path of the catheter axis is reconstructed from two X-ray images, after which the stack of IVUS contours is wrapped around this 3-D catheter centerline. In order to establish the correct rotational position of the stack around the centerline, use is made of "landmarks" or catheter features which are visible in angiograms, as well as in a simulation of these angiograms derived from the reconstructed 3-D contour.

Abstract: An ultrasound diagnosing apparatus comprises an ultrasound transducer for emitting ultrasound beams and receiving reflected beams to form a scanning plane, and for displacing the scanning plane three-dimensionally for N steps; image data processor for obtaining predetermined brightness value data of respective echoes of the received ultrasound beams which define the respective scanning plane and for outputting the brightness value data of the ultrasound beams of the respective scanning plane as one pixel line data; a memory for storing ultrasound image data of M number of ultrasound images into M number of frames, the ultrasound image data of each of the M number of ultrasound images being comprised of N number of the pixel line data produced by the image data processor; writing control circuit for sequentially storing M number of the pixel line data each having a different time phase to the corresponding positions of the respective frames of the memory, the M number of the pixel line data being obtained by c

Abstract: A method for imaging an organ or internal structure within a body to obtain three-dimensional reconstruction of the organ or internal structure. The method includes steps of providing an intraluminal ultrasound imaging system capable of obtaining echographic images of the surrounding of a catheter imaging tip located inside the body of a patient, and a catheter tracking system comprising at least one ultrasound transducer mounted adjacent the imaging tip of an intraluminal ultrasound catheter for insertion into a patient, a plurality of transducers located away from said intraluminal ultrasound catheter so as to form a reference frame, and circuitry for calculating positions of the plurality of frame transducers relative to each other and positions of said catheter tip transducers relative to said plurality of frame transducers.

Abstract: A medical diagnostic ultrasound system is described in which ultrasonic B mode tissue information and Doppler flow information is acquired from a volumetric region of the body and processed together to render a three dimensional image. The three dimensional rendering processes the B mode and Doppler flow information as a function of the spatial location of B mode and Doppler pixels in the volumetric region. The rendering utilizes separate three dimensional rendering parameters for the tissue and flow information, respectively.

Abstract: The present invention relates to a method and an apparatus for processing a plurality of ultrasound images of ductolobular systems in a breast. The operator scans each particular duct system in the breast and saves these axial scan segments. Further, the operator scans the ductolobular systems transaxially. The imaging system, interactively with the operator, aligns the axial scan segments of the duct. This is accomplished by electronically noting the radial direction of the axial scan or by identifying two like image points on respective, sequential axial scan segments. A composite axial scan image in compiled by aligning multiple, sequential axial scan segments together. The associated transductal scan images are mapped to the axial scan segment. The composite axial scan image is displayed with a clockface template of the breast, a vertical, cross-section template of the breast and a three dimensional composite image of the breast.

Abstract: An image processing apparatus includes an ultrasound transducer for sequentially emitting ultrasound beams and receiving respective echoes of the ultrasound beams to produce a scanning plane; a mechanism for displacing the ultrasound transducer to move the scanning plane in a three-dimensional region; a three-dimensional image data generator for sequentially obtaining echo data of the respective ultrasound beams from the echo of the respective ultrasound beams upon receipt of the echo by the ultrasound transducer, and for sequentially generating, based on the echo data of the respective ultrasound beams, brightness value data for each ultrasound beam corresponding to a brightness value for one ?1! pixel in an ultrasound image for the three-dimensional region; a memory, having addresses corresponding to respective pixels in the ultrasound image, for sequentially storing the brightness value data for the respective ultrasound beams generated by the three-dimensional image data generator at the corresponding add

Abstract: An underfluid ultrasound imaging catheter system includes a catheter having a distal end inserted into an underfluid structure, an ultrasonic transducer array mounted proximate the distal end of the catheter wherein the array has a row of individual transducer crystals, a lens mounted on the array for defocusing ultrasound beams in a direction perpendicular to an axis of the array so as to provide a volumetric field of view within which the underfluid features are imaged. Alternatively, the single row of transducer crystals is replaced by multiple rows of transducer crystals so as to provide a volumetric field of view. This imaging catheter system helps an operator see 3-dimensional images of an underfluid environment, such as the 3-dimensional images of fluid-filled cavities of heart, blood vessel, urinary bladder, etc. Features in such wide volumetric field of view can be imaged, measured, or intervened by an underfluid therapeutic device with an aid of the real-time image.

Abstract: A method and device for ultrasonically imaging a body that includes a movable ultrasonic transducer capable of imaging a scanline wherein the scanline is fixed in orientation and spatial position relative to the movable transducer. The device contains a means for sensing transducer position information wherein the sensing means is in communication with an ultrasound console. A computing means computes the spatial position and the orientation of each scanline as the transducer is moved. The scanlines are then presented as a complete image. Alternatively, an electromagnetic transmitter and receiving sensor determine the spatial orientation and position of each scanline in free space. The method of generating a two dimensional ultrasonic image is also disclosed.

Abstract: A 3D ultrasound image processing system which realizes display of 3D ultrasound images on a viewing screen by the use of simple and inexpensive means, the 3D ultrasound images having a cut-out section opened in an region of particular interest to expose to view an internal organ or interior tissue structures in a three-dimensional perspective view.

Abstract: An acoustic imaging device for providing an image of a body in a medium, includes a plurality of acoustic transmit elements and a plurality of acoustic receive elements, an apparatus for activating one of the transmit elements to generate an ultrasonic signal, an apparatus to selectively receive and record from each of the receive elements a set of data representing a phase, amplitude and transit time of the ultrasonic signal, a first computing apparatus for calculating a velocity map of propagation velocity values in each of a plurality of volume elements including the body and the medium using the data set, and a second computing apparatus for calculating a reflectance map, including a coherent sum of reflectance values at selected points in the plurality of volume elements using the data set.

Abstract: An ultrasonic diagnostic imaging system is provided which utilizes a multivariate processor to discriminate between Doppler power signals which were produced by moving tissue, and Doppler power signals which were produced by fluid flow. Discriminated moving tissue Doppler power signals are displayed in a three dimensional spatial presentation.

Abstract: A compounded field of view ultrasound image is derived from correlated frames of ultrasound image data. An operator manually translates an ultrasound probe across a patient target area. Frames of sensed echo signals are processed to detect probe motion without the use of a dedicated position sensor or motion sensor. Motion is detected by correlating the frames for probe translation among as many as 6 degrees of freedom. Image registration then is performed for correlated portions to compound a large ultrasound image. Such image encompasses an area larger than a single field of view image frame for the given manually-scanned transducer probe.

Abstract: An ultrasonic diagnostic imaging system is provided with a scanning guide which assists a user in conducting three dimensional ultrasonic scanning of a patient. The guide is visual or audible or both, and gives the physician a real time indicator by which to gauge the rate and duration of three dimensional ultrasonic scanning. In a constructed embodiment the scanning guide is modulated by a counter coupled to cine memory, in which image frames are stored for three dimensional processing. As the cine memory fills toward capacity with ultrasonic image frames, the scanning guide is modulated in correspondence with the filling of the memory. A visual indicator of the ultrasonic frame sequence in memory is also provided, on which the user can move markers to eliminate frames at the beginning or end of the sequence from the three dimensional reconstruction.

Abstract: An image of an interrogation region of a patient's body is generated from the return signal from an ultrasound pulse, which is directed into the interrogation region by a transducer array, which may be linear (to create a planar image) or planar (to create a 3-D image). The time-domain signal back-scattered to the transducer is sensed at a reference plane (preferably, the transducer plane itself) and is transformed first by a temporal Fourier transform and then by a spatial Fourier transform, in order to generate an angular spectral decomposition of the back-scattered signal. This decomposed reference signal is then propagated to image planes (or lines) at depths other than at the reference plane, throughout the image volume. The resulting propagated signals are then inversely transformed twice, back into the time domain. An entire image is thus reconstructed from the back-propagated signal from a single input pulse.

Abstract: An ultrasound imaging system for generating high resolution, three-dimensional images of the body for medical imaging. The system includes a housing with a rotatable disk at one end having an aperture therein and a plurality of pairs of ultrasonic transducers disposed around the periphery thereof. A flexible member encloses the housing and a fluid filled cavity disposed in the housing in which the transducers are immersed. An ultrasonic transmitter is coupled to the aperture for transmitting ultrasonic energy by way of the aperture, fluid filled cavity and flexible member. A receiver is coupled to the ultrasonic transducers and a processor is coupled to the receiver for sequentially processing reflected ultrasonic energy received by the pairs of ultrasonic transducers to produce a high resolution, three-dimensional image of the body. The system forms a synthetic aperture using the moving ultrasonic transducers.

Abstract: In a method for imaging display of a spatially fixed subject with a primary (wave) radiation directed onto the subject, particularly ultrasound, whereby the imaging display ensues with the echo signals received by an echo signal receiver on the basis of the transit time and/or amplitude thereof with reference to a subject axis directed in the spatial direction of the primary radiation, the subject is located between the primary radiation transmitter/echo signal receiver and a reference surface aligned perpendicular to the spatial direction of the primary radiation and that reflects the primary radiation as an echo signal more strongly than other regions of the subject situated in the field of presentation. The average or expected transit time and/or amplitude of an echo signal of primary radiation passing through the subject that is reflected from the reference surface and received by the primary radiation transmitter/echo signal receiver is calculated or predetermined as reference echo signal.

Abstract: An ultrasound signal is transmitted into the center of the bladder. The received backscatter information is gated so that the data which remains is from a sample volume within the bladder and does not include information from the front or back walls and surrounding tissues of the bladder. The backscatter information is then compared with a preestablished threshold value. If the received backscatter is above a threshold value, it is indicative of a possible urinary tract infection, and an alarm is transmitted to the user.

Abstract: A region of tissue is scanned as a series of 2-D frames. The correlation of substantially homogeneous speckle regions in the frames is determined and is compared with a precalibrated speckle correlation-versus-distance function to give an estimate of the distance between the frames. In some applications, the frames are partitioned into sub-frames, whose correlation values and distances are combined according to predetermined functions to give a distance estimate between the frames as a whole. The reliability of the distance estimates is improved and evaluated in various ways, for example, by comparing combinations of possible distances from end frames via intermediate frames, and by comparing computed frame or sub-frame velocities with a known or estimated transducer velocity. Once the relative distances of the 2-D frames are estimated, a 3-D image is compiled using registration techniques. Image frames need not be parallel.

Abstract: A method for motion encoding of tissue structures in ultrasonic imaging for investigation of living bodies, comprising the steps of obtaining 2D or volumetric data sets (4) by ultrasonic measurements covering a selected region within a living body, localizing at least one tissue structure within said selected region, measuring the movement of said at least one tissue structure within said selected region by correlating said selected region between at least two instants of time, computing from said data sets with respect to said at least one tissue structure a local motion characteristic estimate, and visualizing said at least one structure as well as said motion characteristic estimate.