Abstract: A multi-isotope study is carried out using a plurality of imaging agents which are imaged simultaneously. The information obtained is weighted using as many energy weighting functions as there are isotopes. The weighting reduces "crosstalk" between each of the single-isotope images which are produced as a result of the study. This produces improved results in, for example, dual-isotope (Tc-99m and Tl-201) myocardial perfusion studies.

Abstract: A signal containing piled-up pulses from a scintillation camera head is sampled at a high frequency. Samples are summed to provide a time-integration of pulses which are sampled. When pulses pile up, the tail of the first pulse can be determined by extrapolation, permitting the first pulse to be energy-validated. The overlapping tail of the first pulse and the head of the second pulse are also time-integrated, and the area of the tail of the first pulse is subtracted from the time-integration so obtained. It is then possible to validate the second pulse.

Abstract: A scintillation crystal module of the type having a crystal housed in a backcap which is closed off by a glass window and sealed by an internal seal located between the window and the backcap is modified to include an external seal. The external seal is of moisture-impervious material and is attached to the outer surface of the backcap and the window and bridges over the boundary therebetween. The external seal may be made of an epoxy polyamid or a blocked urethane epoxy copolymer. The outer surface of the module may be sandblasted before the external seal is attached to the module, as by casting the adhesive in a suitable mold.

Abstract: A control panel, which includes a programmable electroluminescent touch screen, is mounted so as to be operable by the radiologist during a PTCA procedure. The system has the capability of displaying, for comparison purposes, synchronized comparable images of the arterial blood flow before and after the PTCA procedure. Synchronized image is achieved by adding or deleting video frames from the end of a patient's cardiac cycle.

Abstract: A housing for an electric device, such as a power transformer or an X-ray tube, comprises a tank which contains electric components of the device and which is filled with an insulating and/or cooling liquid, such as. A lid is arranged at a planar top portion of the tank and hermetically sealed thereto. The lid is at least partially flexible for enabling movement of the lid when the liquid expands and contracts due to heating and cooling, respectively. In a preferred embodiment, the lid comprises a gasket at its periphery and a rigid portion at its center. A frame can be provided for pressing the gasket against the tank. At the frame, at least one rod or spring can be fastened for guiding the movement of the lid perpendicular to the plane of the planar top portion.

Abstract: A control panel, which includes a programmable electroluminescent touch screen and a joystick, is mounted so as to be operable by the radiologist during a PTCA procedure. A bedside monitor displays fluoro and roadmap information during the procedure. The radiologist can adjust the relative weight of the roadmap information to the fluoro information by operating the joystick. The system automatically selects the appropriate roadmap based upon the angular orientation of the camera gantry, or alternatively selects the appropriate gantry position to correspond to that used to produce a satisfactory roadmap.

Abstract: A gantry for a multi-head scintillation camera including a pair of vertically disposed annular plates between which are mounted the scintillation camera heads. The plates are supported on their peripheral edges by rollers which both provide load bearing support and allow plate rotation. A pulley is mounted on one of the plates and is belt-driven by a motor.

Abstract: An arrangement for determining the planar contour of an object including a plurality of light emitters and detectors positioned in a circular planar array. The circular array surrounds the object whose planar contour is being determined. The light emitters are sequentially energized and the resulting signals from the light detectors are utilized for determining the object's planar contour.

Abstract: Photomultiplier tubes are bonded using silicone gel, which cures to a soft state. Small glass or plastic spheres are placed in the gel before it has cured so as to weaken it and make it easier to shear when the photomultiplier tubes are twisted or tipped. The resulting bond is mechanically and optically adequate but not so strong as to make it impossible to remove a photomultiplier tube which must be replaced.

Abstract: The gantry of a scintillation camera is automatically counterbalanced about two parallel axes. One axis passes through the detector. The other axis is a tilt axis about which a gantry structure which supports the detector may be tilted. The gantry is also counterbalanced about an axis of rotation. A collimator may be detachably secured to the detector and automatically identified. The gantry is automatically adjusted to counterbalance it in accordance with the collimator which has been attached to the detector. In the preferred embodiment, the gantry is counterbalanced even when no collimator is secured to the detector.

Abstract: A collimator is designed for use in rotational camera transaxial SPECT in which the camera head is inclined with respect to the axis of rotation. The principal ray of the collimator is offset so that the transaxial plane bisects the angle bounded by the radially outermost collimated rays (cone-beam case) or by the radially outermost fan strips (astigmatic and anamorphic cases.

Abstract: A small scintillation crystal has a surface which is coated with a thin layer of aluminium or cobalt. The aluminium is etched with identification markings, as by a laser.

Abstract: A focusing collimator has a plurality of corrugated strips which are built up in a stack. Within each stacking plane of interest, each strip is shaped in cross-section as a part of a different radial sector of a common predetermined annulus.

Abstract: A detector module for use in scintillation cameras utilizes a plurality of elongated scintillator strips. A temperature gradient is established along the length of each strip. By identifying the particular strip in which a scintillation event has taken place and by measuring the decay time of the scintillation event, two-dimensional information can be developed. This permits a scintillation camera detector to be modularized and largely eliminates the problems of edge packing.

Abstract: A collimator storage device for a collimator having a certain diameter. The device comprises a support, a first collimator storage member having a first slot for inserting the collimator, and a second collimator storage member having a second slot for inserting the collimator. The first and second collimator storage members are mounted at the support in a distance from each other which is smaller than the diameter of a collimator having smallest size such that the first and second slots combine for bearing a smallest size collimator or a collimator having larger diameter therebetween.

Abstract: A collimator is in the shape of a closed curve and has one and only one focal point. The collimator is dimensioned such that, in use, the focal point may be positioned inside the body organ to be imaged. The focal point is caused to densely trace over the body organ of interest to form a tomographic image in less time, without imaging the rest of the body slice.

Abstract: A fan-beam collimator has a plurality of focal lengths. The shortest focal length is located at the center of the collimator. The longest focal length is located at the periphery of the collimator. The focal length increases between the minimum focal length and the maximum focal length.

Abstract: A collimator has a plurality of focal points in the transaxial direction and at least one focal point in the axial direction. The shortest focal lengths are located at the center of the collimator. The longest focal length is located at the periphery of the collimator. The focal length increases between the minimum focal length and the maximum focal length.

Abstract: A gamma ray scintillation camera generating (X,Y) spatial coordinate and Z energy signals relative to detected radiation events. The system provides for calibration of the camera Z signal response as a function of camera face location. The camera signals are converted to their digital equivalents subsequent to which the apparent coordinate locations of detected events as determined by the camera are corrected to their true spatial coordinates based upon correction information stored in the system.

Abstract: A scintillation crystal is heated. A temperature gradient is established across a scintillation crystal inside a scintillation camera system. The decay time of a scintillation flash is related to the temperature of the site at which the corresponding scintillation event takes place. By monitoring the decay time of detected scintillation flashes, as by differentiation, the depth of the scintillation event within the scintillation crystal is determined, thereby leading to improved spatial resolution and improved energy resolution.