Abstract: A radiation detector for an X-ray computed tomography apparatus, has a number of detector modules mounted side-by-side, each detector module having a sensor array composed of a number of sensor elements. For simplifying the maintenance of the detector, each detector module contains an electronic memory arrangement for storing data relating to the calibration of each of the sensor elements.

Abstract: A method (200) for setting up and performing a medical imaging session of a subject using a gamma camera (12, 52) includes selecting (208) an imaging procedure on an input terminal (72). A procedure table (76) is electronically accessed to retrieve at least one of: (1) an identification (210) of a collimator (30) to be used with a detector head (14, 54) in the selected imaging procedure; and (2) an initial imaging position of the detector head (14, 54) for the selected imaging procedure. A currently mounted collimator that is currently attached to the detector head (14, 54) is electronically identified. At least one of: (1) loading (216) the identified collimator onto the detector head (14, 54); and (2) positioning (220) the detector head in the identified initial imaging position, is automatically controlled.

Abstract: A nuclear medical imaging apparatus receives an associated object (18). A radiation detector (12) is equipped with a slat collimator (14) including a plurality of spaced apart slats (114) separating individual detecting elements of an essentially linear array of detecting elements (116). The slat collimator produces planar collimation and results in projection data which is weighted inversely with distance in the projection direction. An image reconstruction processor (34) converts the projection data obtained by the detector (12) into an image, including correction for the inverse distance weighting. The image reconstruction processor (34) includes a memory, a preconditioning operator P (36), a projection operator S (38), and an iterative loop operator (40) which applies the preconditioning operator P (36) and the projection operator S (38) to the memory contents to calculate updated memory contents.

Abstract: &ggr;-ray emissions (14) are detected by a rotating, one-dimensional detector array (18). Slats of a convergent or divergent collimator (16) are mounted between detector elements. The slats are canted by an angle &agr; from focusing on a focal spot (40) on a perpendicular bisector to the detector array. As a detector head (30) revolves around a longitudinal axis (36) of the subject, the head is canted (FIG. 5) to generate angularly offset data sets. Data sets with the detector array rotated to 180° opposite orientations are processed (62) to generate a first derivative data set. Parallel lines or planes (64) of the canted data sets are processed (68) to generate a second derivative data set which is backprojected (70) in accordance with the Radon transform into a three-dimensional image representation.

Abstract: A tomographic imaging system includes a moveable detector or detectors capable of detecting gamma radiation; one or more position sensors for determining the position and angulation of the detector(s) in relation to a gamma ray emitting source; and a computational device for integrating the position and angulation of the detector(s) with information as to the energy and distribution of gamma rays detected by the detector and deriving a three dimensional representation of the source based on the integration. A method of imaging a radiation emitting lesion located in a volume of interest also is disclosed.

Abstract: The present invention provides a high gain collimator producing generally uniform intensity profiles for use in lithography and other applications. A focusing optic is also provided. The collimator includes a reflector and guide channel. The guide channel preferably includes polycapillary tubes and/or microchannel plates. The polycapillary tubes are used to collimate or focus the central portion of the x-ray beam in a circular, elliptic, square, or rectangular shape. A conical, parabolic resonance reflector or grazing incidence reflector with a shape similar to the polycapillary collimator is used to increase the solid angle collected and produce a circular, square, etc. annular x-ray beam whose inside dimensions are approximately equal to the exit dimensions of the polycapillary collimator.

Abstract: An accelerator (10) generates an electron beam (22) of selected energy that is swept (16) up and down. A conveyor (32) moves items (30) through the electron beam for irradiation treatment. An array (40a) of inductive electron beam strength detectors is disposed on a down stream side of the item to detect the energy of the electron beam exiting the item at the plurality of altitudes. The electron beam strength entering and leaving the item are communicated to a processor (54) which determines the absorbed dose of radiation absorbed by the item. The dose information is archived (56) or compared by a parameter adjustment processor (58) with target doses and deviations are used to control one or more of MeV or beam current of the electron beam, the sweep rate, and the conveying speed of the items. Each of the detectors includes a vacuum chamber in which two current transformers (60, 62) disposed on either side of a metal foil layer (64).

Abstract: This invention concerns a device for detecting and locating a radioactive source emitting gamma rays, characterized in that it comprises: first means for determining the direction of the gamma radiation emitting source relative to the centre of the detector comprising: gamma radiation sensing means; a plurality of means for evaluating the gamma radiation flux; means analyzing the gamma radiation flux for determining the direction of-the radiation source; second means for directing the radioactive emitting source comprising mechanical means for causing the device to move, so as to bring its centerline nearer the gamma radiation emitting source; means physically representing the device centerline.

Abstract: A rotating laminar emission camera is provided. The camera includes a detector having a side which detects radiation facing an object being studied. The detector rotates about a central axis (109) perpendicular to the side of the detector facing the object. A collimator (100) constructed of a radiation attenuative material is arranged on the side of the detector facing the object. The collimator (100) including a plurality of spaced apart slats (102) which are tilted at an angle a greater than zero with respect to the axis (109).

Abstract: A subject (10) is disposed adjacent a linear detector array (18) of a nuclear camera. The subject (10) is injected with a radioactive isotope (14) and y-ray emissions indicative of nuclear decay are detected at the detector array (18) as the detector array rotates about an axis of rotation to collect data over a circular field of view. Detectors farther from the axis rotation are sampled at a higher sampling rate such that the are sampled after a generally constant arc of rotation to correct for angular aliasing. The detector array (18) rotates about the axis of rotation in a 1/sin &THgr; pattern with angular offset of the detector array from a longitudinal axis of the subject. This corrects for otherwise uneven sampling. A reconstruction processor (84) reconstructs the identifications of the y-ray receiving detectors, or other indicators of event detection location, and the digital peak values to generate a spherical image representation.

Abstract: An apparatus and method for the automated positioning of a collimator exchange assembly with a gamma camera system is described. A collimator exchange assembly is coupled to a base. During operation of the gamma camera system, the exchange assembly is positioned to the side of the gamma camera system. Prior to transferring collimators between the exchange assembly and the detector heads of the gamma camera system, the exchange assembly rotates into close proximity with the gamma camera system to allow the transfer of collimators between the exchange assembly and the gamma camera system. Once the collimators have been transferred, the exchange assembly then rotates back to the side of the gamma camera system such that the exchange assembly does not interfere with the gamma camera system during the gamma camera study.

Abstract: The invention relates to a method of imaging a target organ in a patient by SPECT, by using a gamma camera having a gamma detector, and by computer reconstructing the distribution of the radioactivity inside the patient's body from planar images, acquired along at least one linear orbit performed in a transverse direction, wherein said gamma detector is perpendicularly provided on its outer surface with a plurality of collimator septa in a mutually parallel arrangement and with at least one raised wall, extending in the longitudinal direction of the detector, transversely positioned to said septa and with a substantial portion extending beyond said septa, said wall and said septa together forming a so-called rake collimator. predetermined minimum diameter detector and a rake collimator.

Abstract: A rotating laminar emission camera includes a detector (22) which detects radiation. The detector (22) has a radiation receiving side (23) that faces an object (e.g., a patient 200) being studied. The detector (22) includes an array of detection elements (106), the array extending in a first direction across the radiation receiving side (23) of the detector (22). The detection elements (106) each individually detect radiation incident thereon. A collimator (100) constructed of a radiation attenuative material is arranged on the radiation receiving side (23) of the detector (22). The collimator (100) experiences relative rotation about an axis (109) substantially normal to the radiation receiving side (23) of the detector (22). The relative rotation is relative to the object being studied. The collimator (100) includes a plurality of spaced apart slats (102) each extending in a second direction across the radiation receiving side (23) of the detector (22).

Abstract: This invention concerns a device for detecting and locating a radioactive source emitting gamma rays, characterized in that it comprises: first means for determining the direction of the gamma radiation emitting source relative to the centre of the detector comprising: gamma radiation sensing means; a plurality of means for evaluating the gamma radiation flux; means analyzing the gamma radiation flux for determining the direction of the radiation source; second means for directing the radioactive emitting source comprising mechanical means for causing the device to move, so as to bring its centerline nearer the gamma radiation emitting source; means physically representing the device centerline.

Abstract: An apparatus and method is disclosed for use in medical imaging including a collimator having an array of positive apertures and an array of negative apertures formed thereon. A housed collimator directed at a detector to essentially eliminate all gamma radiation except that which enters the apertures of the collimator is used. During an imaging operation, a first image of a targeted photon source is generated through the collimator portion having a positive aperture arrangement. A second image of the targeted photon source is generated through the collimator portion having a negative aperture arrangement, wherein the first and second generated images are summed. The summation of these images causes a significant fraction of background artifacts to be reduced from a resulting summed representation of a targeted photon source.

Abstract: An apparatus for mammography is disclosed. The apparatus comprises (a) a bed structure having a patient platform on which a patient lies face down, the patient platform having at least one opening through which the breast of the patient hangs down, (b) a mechanism for holding the breast hanging down through the opening, and (c) a camera for taking a mammographic image of the breast held by the mechanism. The camera includes two scintillation cameras fixed relative to each other in the form of V-shape to accommodate both breasts of the patient simultaneously. The breast holding mechanism includes a breast container for gently accommodating the breast of the patient without causing any pain. The patient platform can rotate, together with the breast container, relative to the camera for three-dimensional imaging.

Abstract: A radiation detector includes a slit collimator. A radiation detector receives radiation which has been received in each of the slits. The aspect ratio of the detector is approximately three, and each semiconductor radiation detector has a transverse dimension which is less than that of its respective slit. A reconstruction processor generates an image indicative of the radiation received by the detectors. The detector may be rotated about a fixed axis. Alternately, the detector may be translated in coordination with its rotation to provide a substantially square field of view.

Abstract: A method for calibration and/or quality assurance of nuclear medicine imaging, in which functional information of the organs to be studied is achieved by inserting radioactive solution emitting detectable radiation in the organs of a phantom simulating the organs to be studied and by detecting the radiation. The filling and emptying of the organs of the phantom to be studied is simulated by regulation of the detectable radiation from the phantom. The organs to be simulated by the phantom are in form of containers filled with radioactive solution, the apparatus further comprising movable isolating parts, like steel plates, between the containers and the gamma camera to isolate radiation from the containers to the camera. The invention is also concerned with an arrangement comprising the apparatus of the invention and a gamma camera.

Abstract: An brain scanning apparatus having a scanner device and a host computer. The scanner radiation detectors detect radiation emitted from a desired portion, or slice, of a brain source. The scanner device contains microprocessors and code which control the movement of the radiation detectors and performs the data acquisition over a number of slices and transmits this data to the host computer. The host computer initiates a scan by sending desired setup parameters to the scanner device and instructing the scanner to begin collecting data. During the scan, acquired data is sent to the host computer and spooled to a hard disk. The computer can be instructed to perform a slice by slice reconstruction of the source brain while the scan is taking place in order to produce a 2-dimensional reconstruction of the mapped brain. A complete 3-dimensional reconstruction of all the compiled slices is performed and visually displayed after acquisition of all the required slices.

Abstract: A compact medical nuclear imaging device, which generates a medical image from gamma radiation, can be held stationary or moved to search a large area for locating a radioactive area of interest. The compact medical imaging device comprises a collimator having an array of collimating channels, a radiation collection module converting the gamma radiation to an electric signal, an electronic module for processing the electrical signal, and a display module for displaying a two-dimensional image of the radiation scene, all of which preferably are assembled together in a single, compact module of a size small enough to permit it to be held and maneuvered by a human operator.

Abstract: A miniaturized scintigraphic device comprising a collimator (1), internally having a multiplicity of equal conduits (10) of determined length, identified and separated by septa (11) of minimum thickness in relation to the energy of the radiation, terminating in a common end plane (12) on the side opposite to the source of the event to be measured, comprising a scintillation crystal structure (2) and at least a photomultiplier (3), in which the scintillation crystal structure is constituted by a multiplicity of individual crystals (20) with polygonal section, each integrally integrated in proximity to the end, oriented towards the photomultiplier (3), of each conduit (10) of the collimator (1), having conforming polygonal section, and arranged in such a way that all the base faces (21) of the crystals (20) oriented towards the photomultiplier (3) are mutually coplanar and lying on a plane parallel to said common end plane (12) of the collimator (1).

Abstract: A single photon emission computed tomography system produces multiple tomographic images of the type representing a three-dimensional distribution of a photon-emitting radioisotope. The system has a base including a patient support for supporting a patient such that a portion of the patient is located in a field of view. A longitudinal axis is defined through the field of view. A detector module is adjacent the field of view and includes a photon-responsive detector. The detector is an elongated strip with a central axis that is generally parallel to the longitudinal axis. The detector is operable to detect if a photon strikes the detector. The detector can also determine a position along the length of the strip where a photon is detected. A photon-blocking member is positioned between the field of view and the detector. The blocking member has an aperture slot for passage of photons aligned with the aperture slot. The slot is generally parallel to the longitudinal axis.

Abstract: A method of imaging a target organ in a patient by SPECT, by using a gamma camera having a gamma detector provided with a fan-beam collimator (2), focusing to a focal line parallel to the patient's body length, and by computer reconstructing the distribution of the radioactivity inside the patient's body from the acquired planar images by using certain reconstruction algorithms. The images are acquired along at least one linear orbit performed in a direction perpendicular to the patient's body, and the collimator focal line is made to travel throughout said target organ during the acquisition. The invention further relates to an equipment for performing this method.

Abstract: A method and apparatus for improving the sensitivity of a position sensitive gamma ray detector and gamma camera. To obtain good position resolution, small effective detector elements are required. However, such small detector elements cause nearly all the gamma rays interacting by Compton scattering to be lost, i.e., they will not contribute to forming the image. The method and apparatus of the present invention takes advantage of the fact that when an incoming gamma ray of known energy is completely absorbed in two separate detector elements the sum of the energy depositions identifies this gamma ray as a valid event. Furthermore, for incoming gamma rays having energies less than 511/2 keV the position where the smallest energy is deposited is the first interaction site and therefore this position can also contribute to forming the image. Alternatively, both interaction sites can be used to form the image, thus improving sensitivity but increasing background noise compared with the preferred embodiment.

Abstract: A system for exchanging and storing collimators for medical imaging devices includes a first frame having a first receptacle and a second frame having a first docking member. A collimator can be attached to and removed from the first receptacle. The first docking member can be positioned adjacent to the first receptacle such that the first docking member can contact the collimator to remove the collimator from the first receptacle. The collimator is coupled to the first docking member while the collimator is removed from the first receptacle.

Abstract: A continuous rotation sampling scheme for use with a nuclear medicine gamma camera facilitates collection of transmission and emission data leading to a reduced overall scan time. The gantry (16) contains a plurality of radiation detector heads (20a-20c) with planar faces and at least one adjustably mounted radiation source (30a). During transmission data collection, the gantry (16) continuously rotates about a subject receiving aperture (18) while the radiation source (30a) continuously rasters back and forth across the field of view. The detected transmission radiation (32a) is reconstructed into an attenuation volumetric image representation by a transmission reconstruction processor (64t). The transmission reconstruction processor (64t) performs a fan beam reconstruction algorithm in each of a multiplicity of planes perpendicular to an axis of rotation.

Abstract: An apparatus is disclosed for use on a collimator of a radio-imaging device. The system includes a stack of plates provided with perforations, the thickness (d) of the plates being less than the diameter of the perforations in the internal entry face of the collimator. The thickness of the span between the perforations is made greater than the thickness of the plates.

Abstract: A coded aperture is placed in proximity of a patient's body and a 2D coded image is acquired in conventional manner. The basic data-acquisition geometry is similar to that used in various coded-aperture systems. According to one aspect of the invention, additional coded images are acquired with different spacings between the aperture and the detector. Alternatively, additional coded images could be acquired with multiple movable apertures or by varying the location of the aperture relative to a patient. Another aspect of the invention resides in the recognition that presently available computer algorithms can process these multiple coded images in such a way as to estimate the integrals of the 3D object over a set of parallel cylindrical tubes extending through the volume of the target object. Such “tube integrals” can be thought of as the output of an ideal collimator where the sensitivity is confined to a tubular region of constant cross-section.

Abstract: A detection head and collimator for a gamma camera. The detection head includes several elementary detectors with semiconductors adjacent to each other to form a detection plane. The collimator is placed in front of the detection plane and includes a number of ducts laid out in a repetition pattern. The shape of the elementary detectors and the repetition pattern are rectangular in the detection plane.

Abstract: A scintillation detector which includes a plurality of discrete scintillators composed of one or more scintillator materials. The discrete scintillators interact with incident radiation to produce a quantifiable number of photons with characteristic emission wavelength and decay time. A light guide is operatively associated with the scintillation crystals and may be either active or non-active and segmented or non-segmented depending upon the embodiment of the design. Photodetectors are provided to sense and quantify the scintillation light emissions. The process and system embodying various features of the present invention can be utilized in various applications such as SPECT, PET imaging and simultaneous PET systems.

Abstract: A radiation detector includes slit collimator. A radiation detector receives radiation which has been received in each of the slits. The aspect ratio of the detector is approximately three, and each semiconductor radiation detector has a transverse dimension which is less than that of its respective slit. A reconstruction processor generates an image indicative of the radiation received by the detectors. The detector may be rotated about a fixed axis. Alternately, the detector may be translated in coordination with its rotation to provide a substantially square field of view.

Abstract: Apparatus for collimating particle emanations, whether photons or material particles, comprises a collimator plate and a motion means. The collimator plate is made of an attenuating material capable of attenuating the particle emanations. The collimator has a plurality of apertures of defined cross-sectional diameter, cross-sectional shape and three-dimensional distribution which restricts the emanations to pass through the plate in a plurality of defined collimated beams. The motion means moves the collimator to enable the plurality of collimated beams to form a defined combined beam having a preselected cross-sectional distribution of flux, when averaged over a specified time. The resolution of the collimator is essentially the cross-sectional diameter of the apertures, which is limited only by technical manufacturing capabilities.

Abstract: A high sensitivity radiation imaging system, aimed to perform sections (or tomographic) images of emitted radiation. This system includes a collimator having at least two openings in which the narrowest cross-section is greater than twice the intrinsic resolution of the detector so that different points of radiation impact can be detected in each opening. The plurality of openings differs in shapes, dimensions or orientations in order to provide a better overlap of their impulse function in the Fourier space. The camera head is displaced by successive steps, the successive steps being of the order of magnitude of a predetermined image resolution. Information collected by the detector is processed by storing locating information corresponding of the impact points for each position of the openings during displacement, and processing the information to reconstruct the radiation volume density function.

Abstract: Disclosed is a tomographic apparatus (100; 200; 300) wherein a camera (10) is provided with a converging collimator (120; 220; 320), and wherein a planar radiation beam makes a scanning movement to move an elongate illumination pattern (125; 225; 325) over the camera (10). In a first embodiment the collimator (120) is a fan beam collimator, and the radiation source (150) is a line-shaped radiation source which is rotatable about its longitudinal axis. In a second embodiment the collimator (220) is a fan beam collimator, and the radiation source (250) is a point-shaped radiation source which is movable along the convergence line (221) of the collimator (220). In a third embodiment the collimator (320) is a cone beam collimator, and the radiation source (350) is a point-shaped radiation source which is rotatable about an axis of rotation (357) which intersects the convergence point (321) of the collimator (320).

Abstract: A multidetector gamma camera arrangement having a first detector and a second detector with each detector including a scintillating crystal and transducer means, the first detector and the second detector abutting to each other with the crystals of first detector and second detector at an angle to one another to enable acquiring two simultaneous views of an organ of the patient.

Abstract: The imaging system has two detectors which can be rotated in a circular path about an object with the angular displacement between the detectors and their radial position with respect to the axis being adjustable. Preferably, the distance of the detectors from the lateral axis is adjustable to increase resolution of the system. A gantry has supports for drive gear rings for the detectors with radial motion mechanisms connecting one detector to the interior surface of a drive gear ring and the other to the exterior of its drive gear ring via a support arm. A drive gear and idler gear move one detector along the circular path and a radial drive motor moves the detectors radially with respect to the axis.

Abstract: A diagnostic apparatus for nuclear medicine capable of performing an operation of counting gamma rays for a TCT simultaneously with an operation of counting gamma rays for an SPECT has a SPECT counter for counting, as the number of photons, gamma rays passed through a SPECT energy window centered at a photoelectric peak of the SPECT gamma rays and a TCT counter for counting, as the number of photons, gamma rays passed through a TCT energy window centered at a photoelectric peak of the TCT gamma rays. The number of photons of the gamma rays passed through the SPECT energy window contains the number of photons of K-X rays generated due to a photoelectric effect produced by the TCT gamma rays in collimators of the detector. A K-X ray processor estimates the number of photons of mixed K-X rays on the basis of the number of photons counted at the TCT counter.

Abstract: A gamma ray collimator assembly comprising a first portion and a second collimator portion, the first and second portions having different gamma ray acceptance angles.

Abstract: The miniaturized gamma camera has all specific functionalities of gamma cameras, with extremely high spatial resolution (about 1-2 mm) and dimensions of about 22 mm×22 mm of active area and total size of about 35 mm×35 mm, such as to fit in one of the surgeon's hands and to be handled with absolute ease.

Abstract: A radiation detection apparatus includes a hand-held probe with a switch assembly removably mounted thereon. The switch assembly having first and second switches, one to initiate transmission of electrical signals representing scintillations detected over a set time period to a remotely located control unit for counting and averaging, and the other to direct the control unit to download and preferably record the counted and averaged scintillation values for further use. The switch assembly has an insulating member for electrically insulating the switches from the probe, and spaced gripping members that releasably grip the probe. A movable stand is provided preferably with a holder for holding the probe. The probe can have a protective cover thereon with a switch assembly mounted onto the probe over the cover.

Abstract: A non-invasive analysis device including a plurality of sensors (110) combined with collimating structures (120) having a common source focus (O) and processing means (300) providing an AND-type combinational logic function of the output of the sensors (110) for sensing two coincidently transmitted beams that are at least slightly angularly correlated.

Abstract: A radiation detection device for gamma radiation is disclosed having an array of crystals optically positioned adjacent an optional collimator, the crystals emitting visible light upon illumination by the incident gamma radiation. An array of photodetectors is optically positioned adjacent the crystal array on the side of the crystal array opposite that of the collimator. A select photodetector in the photodetector array provides an output signal when the select photodetector is illuminated by the visible light. An integrated circuit having an input from the output signals of said array of photodetectors is used to process and output signals indicative of the intensity and position of the gamma radiation.

Abstract: The imaging system has two detectors which can be rotated in a circular path about an object with the angular displacement between the detectors and their radial position with respect to the axis being adjustable. Preferably, the distance of the detectors from the lateral axis is adjustable to increase resolution of the system. A gantry has supports for drive gear rings for the detectors with radial motion mechanisms connecting one detector to the interior surface of a drive gear ring and the other to the exterior of its drive gear ring via a support arm. A drive gear and idler gear move one detector along the circular path and a radial drive motor moves the detectors radially with respect to the axis.

Abstract: A gamma camera system includes a rotatable gantry supporting multiple detector heads each capable of receiving radiation from a region of interest of a subject disposed in an examination region. Each of the detector heads include a collimator which substantially defines the resolution and sensitivity of the respective detector head. At least two of the detector heads include collimators providing different resolution. Preferably, one of the collimators provides a detector head with substantially high resolution and another provides a detector head with substantially high sensitivity. An operator selectively combines image data detected by each of the multiple detector heads. If desired, the operator combine the image data from the multiple detector heads in a variety of manners to obtain images of various resolution and sensitivity from a single imaging procedure. The operator may also selectively weight the contribution that the image data from each of the detector heads has in the overall image.

Abstract: A gamma camera includes detector heads disposed about an examination region. A high energy collimator collimates the radiation received by each of the detector heads. Either a positron emitting radionuclide or a positron emitting radionuclide and a single photon emitting radionuclide is introduced into an object to be imaged. Radiation which is received by the detectors within a coincidence time interval and radiation which is received by either of the detectors but having an energy characteristic of a positron annihilation are used to generate coincidence data. Radiation which is not indicative of coincidence radiation but which has an energy characteristic of the single photon emitting radionuclide is used to generate single photon data. The data is processed and used to generate one or more images of the object.