Abstract: An intravascular MR contrast agent is administered to a living patient. A series of three-dimensional dynamic MR datasets is acquired from the Volume of Interest ("VOI"), beginning after administration of the contrast agent and continuing for a sufficiently long time as to reflect contrast agent enhancement of all arterial and venous blood vessels within the VOI. A three-dimensional MR angiogram of the VOI is acquired after the contrast agent has reached equilibrium. For each voxel within the VOI, enhancement of that voxel as a function of time post administration of the contrast agent is computed. Parameters that distinguish enhancement of voxels relating to the patient's arteries from enhancement of voxels relating to the patient's veins are selected, and the intensity of each voxel in the MR angiogram is scaled in accordance with the selected parameters. A maximum intensity projection reconstruction of the VOI is generated from the MR angiogram in which voxel intensity has been scaled.

Abstract: The present invention relates to the use of inelastically scattered light, particularly fluorescent and Raman scattered light, for determining the location and composition of material within various organs of the human body. The systems and methods of the present invention provide for medical imaging in three dimensions as well as histological information that can be used for diagnosing disease and various medical conditions.

Abstract: By employing controlled setting of a phase-encoding direction in MRI, for imaging a tissue or blood flow composed of spins whose time T.sub.2 is rather short or ranges from 100 to 200 milliseconds, signal levels induced by the blood flow or the like are raised in order to maintain a good signal-to-noise ratio. An image enjoying an excellent depiction ability can be produced without the loss of information of directivities of blood flows or tissues running in diverse directions. An MRI system utilizing the Fourier transform comprises an element for scanning the same region to be imaged of a subject a plurality of times while changing phase-encoding directions, and an element for producing image data of one frame on the basis of MR rawdata of a plurality of frames.

Abstract: Phase of each transducer element of a high intensity focused (HIFU) transducer array is controlled to compensate for phase change introduced by varying velocity through differing tissue along a path towards a treatment volume. The echo of a specific harmonic of ultrasound pulses of moderate intensity and less than HIFU intensity are used to measure the propagation path transit time of each HIFU transducer element that will converge in a treatment volume through nonhomogeneous tissue. The moderate intensity is outside the linear region between molecular velocity fluctuations and pressure fluctuations. Thus, specific harmonic echoes are distributed in all directions from the treatment volume. Temporal delay in the specific harmonic echoes provide a measure of the propagation path transit time to transmit a pulse that will converge on the treatment volume.

Abstract: The invention relates to a magnetic resonance (MR) imaging method for forming images of a part of a human or animal body which is arranged in a steady magnetic field, an MR image being made of the part which is directed transversely to a major axis of an ellipsoid which approximates the part. The method is used, for example for functional examination of a heart of a human body during which MR images are made of the left ventricle of the heart. Because the heart in every body may be oriented differently relative to a feet-to-head axis and relative to an axis transversely to the feet-to-head axis, the major axis of the ellipsoid should be determined so as to enable an MR image to be formed of an imaging plane which extends transversely of the major axis and contains a minor axis of the ellipsoid.

Abstract: A catheter localization system for determining a position of a catheter (1, 2) within a part of the human or animal body (3), comprising at least one catheter (1, 2) having a plurality of acoustic transducers (6) disposed on the catheter in a spaced apart relationship. Each acoustic transducer (6) is arranged to transmit or receive acoustic signals (12, 14). A signal processing unit (8) is coupled to the plurality of acoustic transducers (6) and arranged to selectively energize the transducers (6) and consequent upon acoustic signals (12, 14) received by the acoustic transducers (6) generate a plurality of acoustic transfer functions (24, 28) representative of an effect of the part of the body on the acoustic signals, which signal processing unit (8) further operates to generate data appertaining to a three dimensional representation (36) of the part (4) of the human body (3) in accordance with the plurality of transfer functions.

Abstract: An electrosurgical generator has an output power control system that causes the impedance of tissue to rise and fall in a cyclic pattern until the tissue is desiccated. The advantage of the power control system is that thermal spread and charring are reduced. In addition, the power control system offers improved performance for electrosurgical vessel sealing and tissue welding. The output power is applied cyclically by a control system with tissue impedance feedback. The impedance of the tissue follows the cyclic pattern of the output power several times, depending on the state of the tissue, until the tissue becomes filly desiccated. High power is applied to cause the tissue to reach a high impedance, and then the power is reduced to allow the impedance to fall. Thermal energy is allowed to dissipate during the low power cycle. The control system is adaptive to tissue in the sense that output power is modulated in response to the impedance of the tissue.

Abstract: Temperature in frozen tissue can be measured from magnetic resonance signals from the frozen tissue based on spin-spin relaxation time (T2) or based on relative intensity of the magnetic resonance signals. Short echo times are required, and use of tailored RF pulses, non-Cartesian readouts, and multi-slice and 3D k-space acquisitions are preferably employed.

Abstract: A fluorescence detecting system detects auto fluorescence emitted from an intrinsic pigment in a part of an organism. An excitation light projector intermittently projects onto the part excitation light in the wavelength range which can excite the intrinsic pigment of the organism to emit auto fluorescence. A fluorescence detector extracts an auto fluorescence component in a desired wavelength range from auto fluorescence emitted from the pigment. A net auto fluorescence component in the desired wavelength range is obtained by subtracting a base line component in the desired wavelength range the fluorescence detector detects when the part of the organism is not exposed to the excitation light from a gross auto fluorescence component in the desired wavelength range the fluorescence detector detects when the part of the organism is exposed to the excitation light.

Abstract: A method for acquiring data from voxels in a contour of tissue includes positioning the tissue in a magnetic field. For the present method, a z-gradient is imposed on the contour tissue to spread the spectrum of all of the voxels over a same range of Larmor frequencies. Additionally, voxels in the contour tissue are selectively encoded with different x-gradients and y-gradients to distinguish the various voxels from each other. In the presence of the z-gradient, nuclei of the encoded voxel are tilted and then refocused at a rate proportional to the z-gradient. Due to this refocusing, spin echo signals are generated which are useful for acquiring data from the tissue. The intravoxel z-gradient used for the present invention is the same for all voxels and is greater than either the x-gradient or the y-gradient which are used for encoding. The z-gradient may be substantially constant.

Abstract: A system (10) analyzes signals representative of a subject's brain activity in a signal processor (12) for information indicating the subject's current activity state and for predicting a change in the activity state. One preferred embodiment uses a combination of nonlinear filtering methods to perform real-time analysis of the electro-encephalogram (EEG) or electro-corticogram (ECoG) signals from a subject patient for information indicative of or predictive of a seizure, and to complete the needed analysis at least before clinical seizure onset. The preferred system then performs an output task for prevention or abatement of the seizure, or for recording pertinent data.

Abstract: An apparatus and method for simultaneously obtaining a sample of biological tissue or liquid and measuring the electrical resistance at at least two different frequencies, or dispersion of resistance, of the biological tissue or liquid for the purpose of diagnosis of the condition of the tissue or liquid. The apparatus of the invention includes a main case, which includes a tube and demountable handle; a hook for obtaining a sample of biological tissue and for serving as a passive electrode in contact with the biological tissue; an aspirating needle for obtaining a sample of biological liquid and for serving as an active electrode in contact with the biological liquid or tissue; a liquid collector, which includes a metal conductor in contact with the biological liquid and piston for obtaining a sample of biological liquid and providing an electrode for resistance measurements; a electrical plug allowing electrical connection between the electrodes and an electroimpedancemeter.

Abstract: A medical method and apparatus for the localization and biospy of lesions in a patient body part. A radiopharmaceutical is administered to the patient followed by placement of the body part within a scanner for obtaining emission data. The emission data is converted into Cartesian coordinates which are used to guide a sampling instrument for the biopsy of said lesion.

Abstract: Method and system for measuring the relative concentrations of first and second isotopic forms of a chemical species within a sample. The present invention need not use a laser or high resolution spectrometer. The system typically includes a waveguide cell with good transmission of particular wavelengths of IR radiation, such as a hollow glass fiber waveguide cell. A source emits electromagnetic radiation, which is modulated at first and second wavelength bands that correspond to absorption bands of the first and second isotopic forms of the chemical species, respectively. In certain embodiments, the source is a filtered broad band source, such as a plurality of LEDs. In some embodiments, an FTIR spectrometer may serve as a filtered source and signal detector.

Abstract: A display screen of an image display section is divided into an image display area for displaying an image and an operation panel display area, an image (base image) imaged by an X-ray CT apparatus, for example, is displayed on the upper part (base area) of the image display area, an image (match image) imaged by a MRI apparatus is displayed in the middle part (match area), and an operation panel, which is composed of an operation panel display area 2 of the image display section and respective operation keys for aligning the images, is displayed thereon. When the operation panel is operated and fit points are provided to the images or a region of interest (ROI) is set on the base image, a CPU aligns and composes the respective images based on the fit points or ROI, and displays the fusion image on the lower part (fusion area) of the image display area. As a result, both the images can be compared with each other visually.

Abstract: RF receiving coil device used in a magnetic resonance imaging apparatus capable of acquiring a tomographic image of an object under examination positioned in a static magnetic field along a predetermined direction including quadrature detection coils for detecting an MR signal component along a direction perpendicular to a body axis direction of the object under examination and also perpendicular to a direction of the static magnetic field, and for detecting another MR-signal component along the body axis direction.

Abstract: Continued bleeding into a pocket or hematoma in the cranium could exert pressure on the brain which would move it relative to the cranium to force the brain stem into the medulla oblongata to arrest breathing. Such brain micromovement is detected by projecting bursts of ultrasound into one or both of the temple areas of the cranium or into the medulla oblongata, and the readout of echoes received from different depths is displayed on a screen. The readout of the echoes indicates continued microshifts of the brain relative to the cranium. To differentiate microshifts of the brain relative to the cranium caused by continued intracranial bleeding as distinguished from pulsations of the brain relative to the cranium caused by supply of blood to the brain from the heart and return of blood from the brain to the heart, the timing of the bursts of ultrasound into the cranium is synchronized with the pulse indicated by a heart pulse monitor.

Abstract: A method of measuring the amount of dislocation of the cervical vertebrae of the patient includes a step of defining, on the base posterior view, an end point on a line connecting a point representing the front end of the nasal septum and a point being equidistant from a pair of ocular orbits; a step of determining, on each side of the base posterior view, a point of intersection (or contact) of the "profile of a foramen magnum of a skull" and the region where a condyle of the skull is joined to, or in close proximity to, a superior articular pit of atlas; and a step of defining, on the base posterior view, a bisector of the angle which a line connecting the front end point to one of the points of origin forms with respect to another line connecting the front end point to the other of the points of origin. The amount of dislocation of the cervical vertebrae is determined by means of the bisector.

Abstract: A tool or device for use in interventional MRI has a matrix of electrical conductors formed on or carried by the outer surface of the tool or device so that in use energisation of the conductors can be effect in order to enable the susceptibility of the tool or device to be varied and thus the apparent shape of the tool or device to be varied.

Abstract: The method and apparatus for measuring the transmittance of blood within a retinal vessel detects the intensity of light reflected from illuminated portions of an eye, including the retinal vessel and background fundus, and adjusts the corresponding intensity signals to compensate for reflections from the retinal vessel. In particular, the transmittance measuring method and apparatus constructs an intensity profile function based upon the intensity signals. As a result, the intensity profile function approximates the intensity of light transmitted through the retinal vessel as a function of retinal vessel position. During the construction of the intensity profile function, the transmittance measuring method and apparatus can compensate for at least some of the reflections of light from the retinal vessel which occurred prior to propagation of the light through the retinal vessel, thereby increasing the accuracy with which the transmittance of blood within a retinal vessel is measured.