Abstract: An invention is disclosed for locating a region of interest in the calcaneus. A pair of ultrasound transducers are positioned on the medial and lateral sides of the heel, respectively. The positioning is based on a size of a portion of the body of a subject upon whom the ultrasound assessment of the calcaneus is to be made. In a presently preferred embodiment, the length of the foot from the back to the head of the first metatarsal is used in conjunction with a proportionality constant and an angle, to position the pair of transducers. The positioning so obtained facilitates (i) reproducible measurements and (ii) comparisons of the results obtained in one person with another, because relatively analogous portions of the highly heterogeneous calcanei are assessed in both. In an alternative embodiment, a single transducer is positioned similarly on the heel, operating in pulse-echo mode.

Abstract: Methods, apparatus and systems for characterizing changes in at least one physical property of soft tissue. A series of acoustic pulses is generated and directed into the soft tissue such that at least one of the pulses is of sufficiently high intensity to induce physical displacement of the tissue. Waves reflected off the tissue, or a flexible member that moves with the tissue, are received and measured to estimate at least one characteristic of the physical displacement induced thereby. Repetition of the generating, receiving and estimating steps provides characterization of the at least one physical property over time. Methods, apparatus and systems for characterizing at least one physical property of blood, by generating a series of acoustic pulses and directing the series of pulses into the blood such that at least one of the pulses is of sufficiently high intensity to induce physical displacement of the blood.

Abstract: Systems and methods are disclosed for improving the resolution and quality of an image formed by signals from an array of receivers. Multiple receivers introduce variations in arrival times that can be less than the period of an operating signal, and also less than the period associated with a sampling operation. Thus, multiple receivers allow sampling of fine features of reflected signals that would be considered beyond the resolution associated with the operating signal. Use of multiple receivers also provides an effective sampling rate that is greater than the sampling rate of an individual receiver. Similar advantages can be obtained using multiple transmitters. Such advantageous features can be used to obtain high resolution images of objects in a medium in applications such as ultrasound imaging. Sub-Nyquist sampling is discussed. Accounting for the effects of refraction on pathlengths as a signal passes between two regions of different sound speed allows improved calculation of focus distances.

Abstract: An apparatus and method for the assessment of various properties of bone is provided. A pair of ultrasound transducers are applied to skin on opposite sides of a bony member. The transducers may be single-element or array transducers. An ultrasound signal is generated and directed through the bony member to obtain a bone output signal. A set of parameters associated with the bone output signal is established and processed to obtain the desired bone property including two net time delay (NTD) parameters indicative of differences in transit time for signals taking different paths through bone and soft tissue. Also disclosed is a novel means for acoustically coupling the transducers to skin, as well as a means for establishing bone mineralization through use of both ultrasound and x-ray measurements.

Abstract: The present invention relates to a method and apparatus for non-invasive monitoring of brain density variations. At least two ultrasonic pulses having different frequencies are provided into the brain for transmission therethrough. The reflected ultrasonic pulses are then sensed and the sensed signal data are then processed for determining at least two phase differences between the phases of the at least two reflected ultrasonic pulses and the phases of the at least two provided ultrasonic pulses. A phase of at least a beat frequency is determined in dependence upon the at least two phase differences. Data indicative of a brain density variation are determined based on the at least two phase differences and the at least a beat frequency.

Abstract: A transmission wave field imaging method, comprising the transmission of an incident wave field into an object, the incident wave field propagating into the object and, at least, partially scattering. Also includes the measuring of a wave field transmitted, at least in part, through an object to obtain a measured wave field, the measured wave field based, in part, on the incident wave field and the object. Additionally, the processing of the measured wave field utilizing a parabolic approximation reconstruction algorithm to generate an image data set representing at least one image of the object.

Abstract: The present invention provides a system for improving the accuracy of the measurement of the osteoporosis condition of the human body parts especially bones using more than three parameters, viz., the broadband ultrasonic attenuation (BUA) quantity, the velocity of ultrasound (SOS) in the bone, the broadband ultrasonic back scattering (BUB) intensity, and the Width of received maximum (WORM) values are calculated from received ultrasound signals. The accuracy of each measured diagnostic parameter is improved by measuring the tissue thickness and the squish amount in the coupling pad instead of assuming constant thickness for the tissue. The several operating modes of the device are controlled and the frequency and the timing of the emitted ultrasounds signals are adjusted by using a field programmable gate array. The error generated in the measurement of the bone mineral density due to the variation in the anatomy and the size of the foot, is removed by using a removable footpad.

Abstract: An ultrasonographic apparatus in which the S/N ratio of a compound image is improved operates by combining a plurality of reception beam signals from probes arranged at different positions relative to a sample, converting the combined ultrasonic beam into a luminance signal, and displaying the luminance signal.

Abstract: A description is given of a method of spectral analysis of a radio frequency ultrasonic signal reflected by a structure subjected to echographic examination, comprising the steps of: a) transmitting an ultrasonic excitation signal into a portion of said structure under examination; b) receiving a radio frequency response signal from said structure; c) applying a time-frequency transform to said radio frequency response signal, dividing the radio frequency response signal into a plurality of frequency bands; d) calculating a local spectral parameter from the values of the time-frequency transform.

Abstract: In a medical ultrasound diagnosis apparatus, a reference image and a guidance display are provided as probe operation support information. The reference image contains a recorded probe mark generated based on coordinate data recorded during a past diagnosis and a current probe mark generated based on current coordinate data. A user adjusts a position and an orientation of a probe so that these marks match. The guidance display has a plurality of indicators provided corresponding to a plurality of coordinate components. Each indicator displays proximity and match for each coordinate component. With the probe operation support information, it is possible to quickly and easily match a current diagnosis part to a past diagnosis part.

Abstract: The composite wave obtained by combining a fundamental wave having the center frequency f1 and a fundamental wave having the center frequency f2 is transmitted at least twice for each scanning line while performing phase modulation, and received an echo signal corresponding to each transmission for each scanning line. An echo signal in which harmonic components are canceled out, is extracted for each scanning line, by performing subtraction processing between echo signals which are obtained in this manner and respectively correspond to at least two transmissions. A signal strength difference (or a signal ratio if logarithmic compression is not performed) at each position on the scanned cross-section is calculated by using the f1 frequency component and f2 frequency component contained in the extracted echo signal. An attenuation image representing the signal strength difference at each position on the scanned cross-section is generated by using the calculated signal strength difference.

Abstract: The invention relates to a method for measuring a mean visco-elasticity value for a soft material. Said method using a single probe carrying at least one transducer comprises the steps of: a) inducing, in a constraint zone, at least one burst of mechanical vibrations in order to generate internal shear waves in the tissue propagating from said constraint zone into the tissue, b1) measuring, with said transducer, the transient tissue displacements in at least one first measurement zone in the tissue, said first measurement zone being located away from said constraint zone, c) estimating a mean visco-elasticity of the region of the tissue situated between the constraint zone and the first measurement zone from said measured transient tissue displacements of the tissue in the first measurement zone.

Abstract: Harmonic motion is produced in a subject using vibro-acoustography. An ultrasonic imaging system repetitively interrogates the subject and the Doppler shift in the reflected echo signals is analyzed to measure the phase and amplitude of harmonic motion produced in the subject at different prescribed frequencies. Shear wave propagation through the subject is determined from this information and mechanical properties related to “stiffness” of the subject are determined. A Kalman filter is employed in the phase and amplitude measurement to extract the harmonic motion information from background noise.

Abstract: The present invention provides elastic constant and visco elastic constant measurement apparatus etc. for measuring in the ROI in living tissues elastic constants such as shear modulus, Poisson's ratio, Lame constants, etc., visco elastic constants such as visco shear modulus, visco Poisson's ratio, visco Lame constants, etc. and density even if there exist another mechanical sources and uncontrollable mechanical sources in the object. The elastic constant and visco elastic constant measurement apparatus is equipped with means of data storing 2 (storage of deformation data measured in the ROI 7 etc.) and means of calculating elastic and visco elastic constants 1 (calculator of shear modulus etc. at arbitrary point in the ROI from measured strain tensor data etc.), the means of calculating elastic and visco elastic constants numerically determines elastic constants etc. from the first order partial differential equations relating elastic constants etc. and strain tensor etc.

Abstract: In one embodiment of the invention, there is an ultrasound processing system that communicates images over a single asynchronous serial channel according to a scheme that does not require an isochronous serial channel and that switches among ultrasound imaging modes robustly. For example, the system is configured to packetize ultrasound image data of at least one ultrasound imaging mode into a stream of data frames and to convey the stream of data frames via the asynchronous channel. Each data frame includes indication of the ultrasound imaging mode and includes ultrasound-imaging-mode-specific imaging parameters. Other embodiments exist.

Abstract: An ultrasonic diagnosis apparatus and method wherein both imaging of a contrast effect and imaging of a tissue appearance before and after inflow of a contrast medium can be realized on condition that low-power transmission and a high frame rate are maintained. The ultrasonic diagnostic apparatus includes a transmission/reception unit for transmitting subject ultrasonic waves with a band substantially centered at a fundamental frequency and generating a received signal based on an ultrasonic echo from the subject, a harmonic unit for extracting a signal of a harmonic component of the fundamental frequency included in the received signal and extracting a signal of the fundamental component with the band substantially centered the fundamental frequency included in the received signal, and a display unit for generating a display image based on the extracted harmonic and fundamental components.

Abstract: An ultrasound machine processes ultrasonic data according to acoustoelastic properties of the materials to obtain strain information without specific assumptions with respect to the material properties of the measured material or a variety of different material properties normally not obtained by ultrasound machines.

Abstract: A method of measuring a predetermined parameter of interest in a bone or joint of a subject's body, comprising embedding in the bone or joint an acoustical transmitter and an acoustical receiver spaced from the transmitter to define between them an acoustical transmission channel which includes a portion of the bone or joint exhibiting the predetermined parameter of interest, measuring the transit time of an acoustical wave transmitted through the acoustical transmission channel from the transmitter to the receiver, and utilizing the measured transit time to provide a measurement of the predetermined parameter of interest.

Abstract: The variation in acoustic properties in soft tissues, such as biological tissues, as a function of strain may be modeled to improve elastographic measurements and to obtain direct measurements of strain or material properties and pre-stress.

Abstract: A method for determining a shear elasticity and shear viscosity of a material based on resonance characteristics. A focused ultrasound wave is directed at the material to induce oscillations in the material, and a velocity of the material is measured. A spectrum of frequency of oscillation versus velocity is developed, and the resonance characteristics exhibited by the spectrum are used to estimate the shear elasticity and viscosity of the material.

Abstract: Unipolar, bipolar or sinusoidal transmitters may leave the transmitter in any of various states at the end of one pulse. Undesired acoustic energy may be generated to change states prior to beginning another transmit sequence or pulse. For example, phase inversion for tissue harmonic imaging is performed where two sequential pulses are transmitted with different phases. The first waveform starts at a low state and ends at the low state of a unipolar transmitter. The next waveform starts at the high state. Transmit apodization or spectrum control techniques may require a pattern of waveform starting states different than a current state. Acoustic disruption due to a change of state of the transmitter between transmissions for imaging is minimized.

Abstract: A method and an apparatus for estimating bone age by at least one acoustic signal in an ossification-actuated skeletal structure. The apparatus includes an acoustic transmitter and an acoustic receiver positioned facing each other so that the structure is positioned between them. The structure has at least two bones. The transmitter is adapted for transmitting a signal to cross the structure transversely. An electronic moveable gantry is provided for adjusting the position of the acoustic transmitter and the acoustic receiver in relation to the structure. A computer system is enabled to perform one or more functions to position the moveable gantry; transmit the signal by the transmitter; control the signal transmitted by the transmitter; receive the transmitted signal by the receiver; and estimate bone age responsive to the received signal by at least one bone age calculation formula.

Abstract: This invention relates to a method of analyzing an ultrasound signal. The method comprises obtaining a time series of sequential data frames associated with an ultrasound signal reflected from and/or backscattered from a fixed location of a material under investigation, each data frame comprising a plurality of samples of the ultrasound signal, and subjecting to an analysis a sequence of one or more samples of the ultrasound signal, or a sequence of at least one parameter derived from one or more samples of the ultrasound signal, wherein a result of the analysis is related to one or properties or characteristics of the material. In one embodiment the method may be used for detecting, diagnosing, and/or assessing cancer and/or abnormalities in biological tissue.

Abstract: An ultrasonic transmitting and receiving apparatus capable of obtaining high quality ultrasonic images with reduced effect of side lobes. The apparatus includes: an ultrasonic transducer array including ultrasonic transducers; a drive signal generating unit for generating drive signals for driving the ultrasonic transducers; a transmission control unit for controlling the drive signal generating unit such that ultrasonic waves transmitted from the ultrasonic transducers form at least one ultrasonic beam; a reception control unit for performing reception focusing processing on detection signals obtained based on the ultrasonic echoes to form a reception focal point thereby obtaining plural pieces of measurement data; a storage unit for storing plural different acoustic pressure intensity profiles; and an essential data calculating unit for calculating image data based on the plural pieces of measurement data and the plural different acoustic pressure intensity profiles.

Abstract: An ultrasound imaging system is provided with an interface for receiving user input, and a controller coupled to the interface, the controller being adapted and configured to adjust parameters for a catheter-based ultrasound probe in response to received user input. Preferably, the controller is programmed to receive a user request for a desired imaging depth, determine an imaging frequency that corresponds to the desired imaging depth, and adjust the imaging frequency of the system to the determined imaging frequency that corresponds to the desired imaging depth.

Abstract: Imaging apparatus, is provided, comprising a first device, for obtaining a first image, by a first modality, selected from the group consisting of SPECT, PET, CT, an extracorporeal gamma scan, an extracorporeal beta scan, x-rays, an intracorporeal gamma scan, an intracorporeal beta scan, an intravascular gamma scan, an intravascular beta scan, and a combination thereof, and a second device, for obtaining a second, structural image, by a second modality, selected from the group consisting of a three-dimensional ultrasound, an MRI operative by an internal magnetic field, an extracorporeal ultrasound, an extracorporeal MRI operative by an external magnetic field, an intracorporeal ultrasound, an intracorporeal MRI operative by an external magnetic field, an intravascular ultrasound, and a combination thereof, and wherein the apparatus further includes a computerized system, configured to construct an attenuation map, for the first image, based on the second, structural image.

Abstract: A method and apparatus for lesion or organ definition for the purpose of radiation treatment planning localization and treatment position verification. The apparatus uses a combination of an ultrasound imaging system and a diagnostic imaging system to acquire localization ultrasound images referenced in the coordinate space of the diagnostic imaging system through the use of a position sensing system. The method compares the location of the lesion in the localization ultrasound images with the position of the lesion in ultrasound images taken while the patient lies on the treatment table of a therapy treatment unit, suggests corrective measures to place the lesion in its intended treatment position and executes the correction upon confirmation from qualified personnel.

Abstract: The present invention is an apparatus, method and system for determining the coefficient of elasticity of a target by detecting determining simultaneously two or more critical-angle reflections of an ultrasound wave from the target using an ultrasound transducer that includes a transmitter and two or more receivers and calculating the elasticity coefficients of the target.

Abstract: A device is described that can be easily used to accurately measure and monitor tissue thickness and structure using ultrasound. The device comprises a remote control and data processing unit, a handheld ultrasound transducer with an integrated position sensor.

Abstract: A method for the in vivo non-invasive characterization of the material and architectural properties of a bone in which an ultrasonic wave is introduced into a bone in such way as to produce one or more guided wave modes within the bone, and the signals emerging from the bone are stored and analyzed to determine the propagation characteristics of the guided wave/s. These measured guided wave propagation characteristics are then processed to obtain estimates of desired bone properties such as cortical thickness, bone density and bone elastic constants. The invention also includes an unltrasound arrangement with movable transducers.

Abstract: The invention relates to a method and system for determining a parameter representing an acoustic property of a material. The method comprises: generating an acoustic pressure wave in said material originating from a localized position; placing a plurality of acoustic receivers (6, 7) at mutually differing distances from the acoustic source (3); transforming a plurality of measured acoustic signals to represent field values in a common computational point; computing a signal representing a measure of overlap between said transformed plurality of acoustic signals as a function of said numerical estimates of said acoustic property parameter and deriving said acoustic property parameter from said overlap signal. Since the invention uses acoustic sources that are well localized in the material, the velocity calculations are simple and the geometry of the acoustic receivers in relation to the acoustic source can be exactly taken into account.

Abstract: System and method for automatically measuring the delay of tissue motion and deformation. For example, asynchrony may be measured between the left and right ventricles and within the left ventricle. A measurement feature may be defined by default or obtained using a user input. A reference time and a search interval are identified. The search interval may be based on the reference time, or input or modified by a user. A time delay of the measurement feature within the search interval is calculated for each sample. At least one color is assigned to the samples corresponding to the calculated time delay.

Abstract: A bone strength measuring instrument and method is provided for obtaining thickness values of cortical bone, cancellous bone and tissue in a human body part by applying an ultrasonic wave to a measured portion of the human body. Ultrasonic transmitters and receivers can be positioned in contact with the human body to provide a set thickness for the human body while processing the received signals transmitted through and reflected from the human body portions to determine a first wave higher in speed and a second wave lower in speed. Prior to making the measurements, a preliminary measurement procedure can be utilized to optimize the desired measurement site. An acoustic speed of the second wave in a cancellous bone can be assumed to be constant and transit times can be calculated and respective thickness values of the soft tissue of cortical bone and cancellous bone can be determined to indicate the bone strength.

Abstract: Methods and systems for determining a proximity between a medical probe (such as, e.g., the tip of the medical probe) having an ultrasound transducer and a tissue surface, is provided. The ultrasound transducer is operated in a first resonant mode to transmit a first ultrasound signal that intersects the tissue surface to create a first reflected ultrasound signal, and operating in a second different resonant mode to transmit a second ultrasound signal that intersects the tissue surface to create a second reflected ultrasound signal. The first and second reflected ultrasound signals are received, e.g., by the ultrasound transducer, and a proximity between a portion of the medical probe and the tissue surface is determined based on the received first and second reflected ultrasound signals.

Abstract: The method decomposes the radio frequency signal into sub-bands by filtering, for example with a time-frequency transform. From the coefficients acquired through decomposition a matrix of spectral coefficients is obtained, from which local estimators are obtained, constituted in particular by the coefficients of the interpolating polynomials. The statistical distribution of the local estimators is evaluated in windows overlaid on the ultrasound frame. The conformation of the distribution histograms of the spectral coefficients provides a parameter which, combined with the local estimators, provides weighted local estimators, which contain spectral information useful in the identification of specific structures in the organ subjected to ultrasound analysis.

Abstract: An ultrasonic diagnosing apparatus capable of improving an SN ratio and emphatically displaying characteristic tissues by acquiring information unique to tissues such as organs, bones, etc. in a living body. The ultrasonic diagnosing apparatus includes: a B-mode image data generating unit for generating first image data based on intensity of detection signals obtained by transmitting and receiving ultrasonic waves having a plurality of frequency components; a frequency component extracting unit for extracting at least one frequency component from the detection signals; a frequency image data generating unit for generating second image data based on intensity of the extracted at least one frequency component; and an image selecting unit for selecting at least one of the first image data and the second image data.

Abstract: An erythema meter includes a probe, a light source of one or more specific probing and reference wavelengths, and an acoustic detector which determines the level of erythema present in the dental pulp chamber of a tooth. The probing and reference wavelengths are delivered in pulsed or amplitude modulated fashion through the probe, thereby permitting electronic identification and filtering of the received data. The absorption of the light wave raises the temperature of the material in the tooth and causes it to expand, thus creating tiny shockwaves which are picked up with the acoustic detector, revealing information on the location of blood and the quantity of blood inside the tooth. The erythema meter accurately measures the erythema, or inflammation, within the tooth in a qualitative and quantitative manner.

Abstract: There are provided an ultrasonic imaging system and method which can correct a phase shift effect to image a real change in acoustic impedance in a living body. An ultrasonic probe transmits an ultrasonic beam to an object to receive an echo. A transmit beamformer transmits a transmit signal via transmit/receive SWs to the probe in delay time matched with a transmit focal point according to the signal under the control of a control system. An ultrasonic signal returned from the object to the probe is converted to an electric signal by the probe to be transmitted via the transmit/receive SWs to a complex receive beamformer. The complex receive beamformer performs dynamic focus adjusting delay time according to reception timing. A phase shift correction part uses the output of the complex beamformer outputting beams of a real part and an imaginary part to correct phase shift. due to frequency-dependent attenuation, correct phase shift in the lateral direction of the beam, or correct both.

Abstract: Tissue mimicking materials for elastography phantoms have elastic, ultrasound, and magnetic resonance characteristics that are characteristic of human soft tissues and well suited for the calibration and performance assessment of elastography imaging systems. In one embodiment, the material is formed from a base material containing an oil dispersed within a gel matrix and at least one inclusion formed from a gel. In another embodiment, the material is formed from a gel-forming material suffused throughout an open-cell reticulated mesh matrix.

Abstract: A method for categorizing whole-breast density is disclosed. The method includes the steps of exposing breast tissue to an acoustic signal; measuring a distribution of an acoustic parameter by analyzing the acoustic signal; and obtaining a measure of whole-breast density from said measuring step. An apparatus is also disclosed.

Abstract: The present disclosure provides methods, systems, techniques and apparatus related to an instrumentation used to classify tissue before and/or during removal. The tissue can include any hard tissue/soft tissue interface, such as a cataract within a lens. Before an operation, an ultrasound image can be provided that gives a full scan of the targeted region, e.g., a lens, and provide a hardness profile. The profile could include a two or three dimensional map of the tissue hardness, assisting a surgeon to choose a suitable surgical procedure and strategy. During the operation, hardness measurements can be carried out real-time, in a constant manner, while the surgeon is working. This data can allow the handpiece to automatically adjust to the surgical conditions including the tissue hardness, increasing surgical performance, decreasing surgical procedure time and reducing the rate of complications.

Abstract: Improved acoustic attenuation materials and applications are provided. An improved acoustic attenuation material may include a woven layer of fibers made of porous polymers, such as porous polytetrafluoroethylene (PTFE), that include interstitial space. An improved acoustic attenuation material may include sheets of porous polymers interleaved with layers of epoxy. The sheets of porous polymers may include through holes. An embodiment of an ultrasonic transducer that includes a backing with woven layers of porous PTFE fibers is provided. The ultrasonic transducer that includes a backing with woven layers of porous PTFE fibers may be used in a three-dimensional ultrasound imaging apparatus. An embodiment of an ultrasonic transducer that includes a plurality of sheets of porous PTFE interleaved with layers of epoxy is provided. The ultrasonic transducer that includes a plurality of sheets of porous PTFE may be used in an ultrasonic imaging catheter.

Abstract: An ultrasonic apparatus has a pulse transmission and reception unit, an envelope curve detection unit, a time difference detection unit, and an attenuation characteristic obtaining unit. The pulse transmission and reception unit transmits a first transmitted pulse that a frequency increases with time and a second transmitted pulse that the frequency decreases with time, further receives a first received pulse corresponding to the first transmitted pulse and a second received pulse corresponding to the second transmitted pulse. The envelope curve detection unit detects a first envelope curve based on the first received signal and a second envelope curve based on the second received signal, respectively. The time difference detection unit detects a time difference between the first envelope curve and the second envelope curve. The attenuation characteristic obtaining unit obtains a frequency dependent-attenuation characteristic of an ultrasonic base on the time difference.

Abstract: A method and apparatus for controlling access of individuals to a service, device or location in order to restrict access to members of a particular age and/or gender category, by machine-sensing a predetermined biometric characteristic of the individual indicative of the particular age and/or gender category, and utilizing the machine-sensed characteristic for automatically controlling access of the individual. The method and apparatus are particularly suited to controlling access of children to certain Internet sites, TV programs, chat rooms, or other places inappropriate to children.

Abstract: An invention is disclosed for locating a region of interest in the calcaneus. A method and apparatus are disclosed that use a pair of ultrasound transducers for ultrasound assessment of various properties of bone. The invention includes positioning the transducers on the medial and lateral sides of the heel, respectively. The positioning is based on a size of a portion of the body of a subject upon whom the ultrasound assessment of the calcaneus is to be made. In a presently preferred embodiment of the invention, the length of the foot from the back to the head of the first metatarsal is used in conjunction with a proportionality constant and an angle, to position the pair of transducers. The positioning so obtained leads to the ability to make both (i) reproducible measurements and (ii) to be able to compare the results obtained in one person with another, because relatively analogous portions of the highly heterogeneous calcanei are assessed in both.

Abstract: The therapeutic ultrasound waveform is used as a source of stress or ARFI pushing pulse. When the therapeutic ultrasound waveform ceases, diagnostic ultrasound is used to measure the strain, such as measuring tissue displacement. The displacement over time after release of the stress indicates tissue characteristics. The tissue characteristics may be monitored to determine when sufficient therapeutic results are obtained.

Abstract: An impedance model of tissue is useful for describing conductivity reconstruction in tissue. Techniques for determining and mapping conductivity distribution in tissue supply useful information of anatomical and physiological status in various medical applications. Electrical Impedance Tomography (EIT) techniques are highly suitable for analyzing conductivity distribution. Electrical characteristics of tissue include resistive elements and capacitive elements. EIT techniques involve passing a low frequency current through the body to monitor various anatomical and physiological characteristics. The system can interrogate at multiple frequencies to map impedance. Analytical techniques involve forward and inverse solutions to boundary value analysis to tissue characteristics.

Abstract: Elastographic images provide visualization in two or three dimensions of RF ablation lesions to guide in the ablation process. Compression may be applied using the RF probe. A similar technique may be applied to in vivo imaging of soft tissue without ablation.

Abstract: A system and method capable of measuring the fat content in the target organ by the gray level distribution of pixels forming a ultrasonic section image and a recording medium of recording a fat content measuring program are disclosed. In order to quantify the fat content of the target organ from the information of the stored ultrasonic section image, a target section and a comparative section in each of the longitudinal sections are set, and a representative gray level value of the respective section is calculated, thereby the fat content of the target section is quantified in a numerical value relative to the representative gray level value of the comparative section.

Abstract: A hybrid calibration method uses an calibration phantom (exterior reference) scanned simultaneously with the patient, and one or more known tissues of the subject (interior reference) to create a hybrid calibration reference that improves the measurement of tissue densities throughout the body. In addition, the calibration method is used to quantitatively define boundaries of tissue and organs for more accurate measurements of lengths, areas and volumes. Another aspect of the invention uses the calibrated images to quantitatively preset absolute window/levels for filming and image display, which provides standardized viewing for diagnostic purposes.