Abstract: The invention provides methods and apparatus for detecting radiation including x-ray, gamma ray, and particle radiation for nuclear medicine, radiographic imaging, material composition analysis, high energy physics, container inspection, mine detection and astronomy. The invention provides detection systems employing one or more detector modules comprising edge-on scintillator detectors with sub-aperture resolution (SAR) capability employed, e.g., in nuclear medicine, such as radiation therapy portal imaging, nuclear remediation, mine detection, container inspection, and high energy physics and astronomy. The invention also provides edge-on imaging probe detectors for use in nuclear medicine, such as radiation therapy portal imaging, or for use in nuclear remediation, mine detection, container inspection, and high energy physics and astronomy.

Abstract: The present invention discloses an apparatus for use in medical imaging including a readout circuit having an input for receiving a detection signal corresponding to a photon hitting a radiation detector, wherein the readout circuit is adapted to output, in response to receiving said detection signal, a pulse signal having a leading edge encoding a time-stamp of said photon and a width encoding the energy of said photon. A method of reading out detection signals from a radiation detector of a medical imaging apparatus is also provided.

Abstract: A programmable memory is provided in each of a plurality of detector modules arrayed in a positron emission tomography (PET) scanner. Each detector module memory stores data associated with its respective detector module. Each memory may be coupled to a processor via a transmission bus. A display device may be coupled to the processor for displaying information relating to information obtained from the detector module memories.

Abstract: In positron emission tomography (PET), a detector's response to scattered radiation may be different from its response to unscattered (true coincidence) photons. This difference should be accounted for during normalization and scatter correction. The disclosure shows that only a knowledge of the ratio of the scatter to trues efficiencies is necessary, however. A system and method are disclosed for measuring the scatter/trues detection efficiency ratio, as well as for applying this compensation during the scatter correction of PET emission data. PET detector efficiencies are measured in two steps, the first using a plane radiation source, and the second using a plane radiation source in combination with a scattering medium. A ratio of the scatter and trues detection efficiency is obtained from this data for each detector/crystal, and is applied as a correction factor to PET data obtained during medical imaging processes.

Abstract: Time-of-flight (TOF) clinical data collected during a PET scan are very sparse and have significant size. These data undergo TOF axial rebinning and azimuthal mashing if histogrammed data-based reconstruction algorithms are used. In a clinical environment, TOF compression is typically performed by the hardware rebinner. Normalization data, acquired on a regular basis and used for estimation of some norm components, are compressed by the hardware rebinner in a similar manner. This disclosure presents simple update iterative algorithms for crystal efficiencies norm component estimation from TOF compressed normalization data. Previously known methods are not directly applicable since the compression procedure significantly complicates normalization data model equations. The iterative algorithms presented herein have advantages of being easily adapted to any acquisition geometry, and of allowing estimation of parameters at crystal level when a number of crystals is relatively small.

Abstract: This invention features an integrated single photon emission computed tomography (SPECT)/transmission computed tomography (TCT) system for cardiac imaging including an open arc-shaped frame. A collimator system is shaped to approximately match the thoracic contour of patients having different sizes and weights and shaped to surround and position the collimator closely proximate a heart of a patient of said patients encompassed by at least one predetermined image volume for optimizing collimation of radiation photons emitted from the heart. An arc-shaped detector system is coupled to the collimator subsystem having a shape closely matching the shape of the collimator subsystem for detecting collimated radiation photons from the collimator subsystem and generating output electrical signals.

Abstract: A method is disclosed for determining positron emission measurement information in the context of positron emission tomography. The method includes carrying out a positron emission measurement, in a body area of a subject to be examined, to record positron emission measurement information with point resolution and determining a time frame of the measurement by, at the same time, generating images of the body area to be examined with a relatively higher time resolution and with point-resolved image data, using a second imaging method. Further, a local shift of points of individual images of the second imaging method is determined, caused by movement processes of the subject to be examined, and as a function thereof, of the positron emission measurement information for at least a part of the measurement period and of the body area to be examined. Finally, the positron emission measurement information is adjusted as a function of the determined shift.

Abstract: A single photon emission computed tomography (SPECT) system for cardiac imaging including an open arc-shaped frame. A collimator subsystem is shaped to approximately match the thoracic contour to optimize the geometric efficiency for detecting photons emitted from the heart of patients having different sizes and weights and shaped to surround and position the collimator subsystem closely proximate a heart of a patient of the patients encompassed by at least one predetermined image volume for optimizing collimation of radiation photons emitted from the heart. The collimator subsystem is facilitated by a tracking system that is capable of quickly bringing up the collimator component, which meets a specific set of collimation requirements, into place for imaging.

Abstract: A representative positron emission tomography (PET) system includes a positron emission tomography detector having one or more silicon photomultipliers that output silicon photomultipliers signals. The PET system further includes a calibration system that is electrically coupled to the silicon photomultipliers. The calibration system determines a single photoelectron response of the silicon photomultipliers signals and adjusts a gain of the silicon photomultipliers based on the single photoelectron response.

Abstract: Determining the position of a radioactive source in a PET system. Detecting a scatter coincidence event characterized by a full-energy photon detected at a first detector and partial-energy photon at a second detector. Measuring the arrival time difference between the partial energy photon and the full energy photon. Measuring the energy of the partial-energy photon. Determining a scattering point as a function of the position of the first detector, the position of the second detector, the energy of the partial-energy photon, the energy of an unscattered photon, the mass of a scattering electron, and the speed of light. Determining the position of a radioactive PET source along a line between the scatter point and the first detector as a function of the distance between scatter point and the first detector, the distance between scatter point and the second detector, and the measured time difference.

Abstract: A gamma camera (8, 180) includes at least one radiation detector head (10, 12, 210, 212). At least one such radiation detector head (10, 12, 210, 212) includes a plurality of capacitive elements (60, 260, 76, 276) disposed over at least a radiation sensitive portion (50) of the radiation detector head. A proximity sensor monitor (62) is coupled with the plurality of capacitive elements to detect proximity of a subject to the radiation detector head based on a measured electrical characteristic of the capacitive elements. A collision sensor monitor (64) is coupled with the plurality of capacitive elements to detect conductive electric current flowing between spaced apart parallel conductive plates (66, 67) of the capacitive element responsive to mechanical deformation of the spacing between the plates.

Abstract: The invention relates to a tomography arrangement with a tubular measuring chamber and a monitoring facility. This monitoring facility includes at least one first video camera focusing on the measuring chamber and at least partially optically recording the same, said first video camera operating in the non-visible light wave range, in order to record moving images and an image output unit for outputting the moving images as well as a first illumination facility focusing on the measuring chamber, which, during operation, illuminates the measuring chamber in the same light wave region, in which light wave range the first video camera operates. The invention also relates to a method for monitoring persons.

Abstract: A method and system for compensating truncated transmission projection data used for attenuation correction in a SPECT apparatus. The method and system include generating an initial estimate of a transmission reconstruction without modeling source geometry or detector collimator response and refining the transmission reconstruction by using the initial estimate with a modified model of the source geometry and the collimation geometry.

Abstract: A positron emission tomography (PET) scanner is provided which uses information on the time-of-flight difference (TOF) between annihilation radiations for image reconstruction. The scanner has detection time correction information (memory) corresponding to information on coordinates in a radiation detection element (e.g., scintillator crystal), in the depth and lateral directions, at which an interaction has occurred between an annihilation radiation and the crystal. Reference is made to the detection time correction information, thereby providing information on time-of-flight difference with improved accuracy. As such, an improved signal to noise ratio and spatial resolution are provided for image reconstruction using time-of-flight (TOF) difference.

Abstract: A constant fraction discriminating circuit outputs timing information corresponding to an event corresponding to a detected photon for providing nuclear medicine imaging. The constant fraction discriminating circuit includes a stripline or microstrip delay element.

Abstract: A nuclear medicine diagnosis apparatus comprising a mechanical collimator for effecting passage in a given direction of photons with given energy emitted from an object injected or dosed with a drug containing a radioactive isotope; a former-stage detector for detecting positional information at a point of reaction of photons having passed through the mechanical collimator and information on the momentum of charged particles generated by the reaction; a latter-stage detector disposed in the subsequent stage of the former-stage detector to detect information on the photons having been scattered by the former-stage detector; and image reconstruction means for reconstructing an image from detection information having been collected from the former-stage detector and latter-stage detector, wherein the image reconstruction means is built so that differentiation is carried out on the information on the photons having passed through the mechanical collimator and the information on the photons having been scattered b

Abstract: A combination rigid imager and obturator for real-time localization of a region of interest during the performance of a surgical procedure that includes: a) a rigid imaging grid preferably made up of an array of gamma radiation position sensitive photomultipliers; and b) an obturator inserted through the rigid imaging grid into a mass containing a region of interest and including: 1) an outer tube having a first closed end and a distal open end; and 2) an inner tube having an inserted end that includes a radioactive tracer and a remote end inserted into the distal open end; wherein the first closed end is inserted into the mass containing a region of interest and the radioactive source provides a marker for the region of interest during the performance of a surgical procedure.

Abstract: A combination rigid grid positioning system, stereotactic gamma imager and an obturator for real-time localization of a region of interest during the performance of a surgical procedure including: a) a rigid grid positioning system including a mechanism for the acquisition of images useful in calculating the spatial location of a region of interest in a mass under study; and b) an obturator inserted through the rigid grid positioning system made up of: i) first and second generally parallel capillary tubes for the introduction thereto and the removal therefrom of a radioactive fluid interconnected at a point of connection; and ii) a reservoir for the radioactive fluid at the point of connection; wherein the reservoir is inserted into the mass containing a region of interest and the radioactive fluid provides a marker for the region of interest during subsequent imaging and thereby specific localization of the region of interest during subsequent procedures.

Abstract: A gamma ray detector module includes at least one scintillation detector configured to operate in a dot-decoding mode, or at least two scintillation detectors configured to operate in a line-decoding mode, wherein the at least one scintillation detector is each coupled to a single photodetector, and wherein the at least two scintillation detectors are coupled to at least two photodetectors arranged substantially along a line; and at least four scintillation detectors configured to operate in a plane-decoding mode, wherein the at least four scintillation detectors are coupled to a plurality of photodetectors arranged in a two-dimensional array.

Abstract: A method and apparatus for the integration of an ultrasound transducer with a SPECT imaging system is disclosed. The ultrasound transducer allows the delivery of particle-born drug therapies or thermally active therapies at the same site detected with SPECT imaging. The system includes a SPECT imaging subsystem; an ultrasound transducer for producing a signal representative of applied ultrasound and signally coupled to the SPECT imaging subsystem; and co-registering means for co-registering the signal representative of applied ultrasound in a coordinate system of SPECT imaging subsystem. The SPECT subsystem may be replaced with a SPECT/CT combined system to provide morphology that allows for treatment planning. In another embodiment, the ultrasound transducer can be used intermittently with the sequential gathering of SPECT images for tracking time-varying properties of the binding of specific SPECT contrast agents to biomarkers of disease.

Abstract: An apparatus for imaging an eye includes a housing and a system of optical components disposed in the housing. The apparatus is capable of operating in a line scanning laser ophthalmoscope (LSLO) mode and an optical coherence tomography (OCT) mode. The system of optical components can include a first source to provide a first beam of light for the OCT mode and a second source to provide a second beam of light for the LSLO mode. In the OCT mode, a first optic is used that (i) scans, using a first surface of the first optic, the first beam of light along a retina of an eye in a first dimension, and (ii) descans, using the first surface, a first light returning from the eye in the first dimension to a detection system in the OCT mode. In the LSLO mode, the first optic is used where the second beam of light passes through a second surface of the first optic.

Abstract: An imaging system (10) comprises at least one radiation detector unit (16) disposed adjacent a field of view (20) to detect and measure radiation from the field of view (20). The detector unit (16) includes multiple detection modules (18) which each detects radiation from a prespecified region of the field of view (20), each region being a fraction of the field of view. One or more pinholes (52) are associated with the detector unit (16). Each pinhole (52) receives radiation from the prespecified region of the field of view (20) and transmits radiation to one or more associated detection modules (18).

Abstract: A system for generating time-of-flight (TOF) positron emission tomography (PET) projection data includes a direct memory access rebinner constructed as a digital FPGA pipeline for rebinning TOF coincidence data in accordance with a number of projection space mapping algorithms, such as single-slice rebinning (SSRB) and reduced multiple-slice rebinning (MSRB), together with less precise transaxial and/or axial sampling.

Abstract: An imaging system (10) includes at least one radiation detector (20) disposed adjacent a subject receiving aperture (18) to detect and measure at least one of emission and transmission radiation from a subject, the detector (20) at a plurality of projection angles. A processor (64) determines which radiation data belong to a field of view of the radiation detector (20) at each projection angle. An image processor (70, 72) iteratively reconstructs the radiation detected only in the determined field of view into image representations. Truncated data is compensated by supplying the untruncated data from the projections taken at different angles at which the truncated data is untruncated.

Abstract: Equipment for imaging a target organ in a small animal by SPECT uses the LOrA technique, wherein each gamma detector of the imaging system includes a plurality of sensitive crystals, curved to a segment of an essentially annular body, and a rake collimator with a small slit width.

Abstract: A method of reconstructing time-of-flight (TOF) images includes obtaining a profile of a subject to be imaged in an examination region (14) of an imaging system (10), Events associated with radiation emitted from the subject are detected and converted to electronic data. Electronic data attributable to radiation events located outside the profile are removed and images are reconstructed from the remaining electronic data.

Abstract: A radiological imaging apparatus of the present invention comprises an image pickup device and a medical examinee holding device that is provided with a bed. The image pickup device includes a large number of radiation detectors and radiation detector support plates. A large number of radiation detectors are mounted around the circumference of a through-hole and arranged in the axial direction of the through-hole. The radiation detectors are arranged in three layers formed radically with respect to the center of the through-hole and mounted on the lateral surfaces of the radiation detector support plates. Since the radiation detectors are not only arranged in the axial direction and circumferential direction of the through-hole but also arrayed in the radial direction, it is possible to obtain accurate information about a ?-ray arrival position in the radial direction of the through-hole (the positional information about a radiation detector from which a ?-ray image pickup signal is output).

Abstract: A detector head having a small field of view, for example one which receives information from less than half a body imaged, is used to form a transmission attenuation map. The same detector head both receives information for the transmission attenuation map and also receives imaging information e.g. from a radioisotope.

Abstract: A device and method for acquiring Single Photon Emission Computed Tomography (SPECT) data. In particular, a method of acquiring data using a gamma camera detector with a collimator, such as a slotted, inverse fan beam collimator, for example. An example collimator that can be used for the method is one comprising: a slot substantially parallel to the axis of rotation of a SPECT scanner; a plurality of plates, each one of the plates being substantially perpendicular to the slot and also being substantially parallel to a transaxial direction of the SPECT scanner; and a detector associated with the slot and the plurality of plates such that, through any motion of the scanner, the slot, the plates and the detector retain their relative positional relationship.

Abstract: A combined PET and X-Ray CT tomograph for acquiring CT and PET images sequentially in a single device, overcoming alignment problems due to internal organ movement, variations in scanner bed profile, and positioning of the patient for the scan. In order to achieve good signal-to-noise (SNR) for imaging any region of the body, an improvement to both the CT-based attenuation correction procedure and the uniformity of the noise structure in the PET emission scan is provided. The PET/CT scanner includes an X-ray CT and two arrays of PET detectors mounted on a single support within the same gantry, and rotate the support to acquire a full projection data set for both imaging modalities. The tomograph acquires functional and anatomical images which are accurately co-registered, without the use of external markers or internal landmarks.

Abstract: In a radiation detector (10) for a time of flight positron emission tomography (PET) scanner (2), a radiation sensitive member (20) generates a signal (22) indicative of a radiation detection event. A time to digital converter (34) includes digital delay elements (40) operatively interconnected as a ring oscillator (36, 36?) and readout circuitry (50, 52, 60, 82, 84, 86, 88) configured to generate a timestamp for the radiation detection event based at least on a state of the ring oscillator when the signal is generated. Delay trim elements (46) operatively connected to the digital delay elements set a substantially common delay for the digital delay elements.

Abstract: The invention provides a radiation detection device (1) for obtaining an image of a part of a test animal or human using high-energy radiation, comprising a detection chamber, a plurality of pinholes distributed all around the detection chamber over at least one pinhole wall, at least one framing wall having an opening for the high-energy radiation, at least one detector which is designed for detecting high-energy radiation, in which a plurality of image fields are provided on the at least one detector, in each case having one beam path from a part of the detection chamber to at least one detector, in which at least one of the at least one pinhole wall and the at least one framing wall is displaceable in such a manner that at least one of the plurality of image fields can be modified in size and/or direction. This provides the possibility to image an object at several angles, or to image a larger or a different part thereof, so that the entire device can be used in a more flexible manner.

Abstract: A first ?-ray generating in a body, caused by a PET pharmaceutical, and a second ?-ray emitted from a ?-ray source and transmitting through the body are detected with a radiation detector. The emission image information (E image information), E1, E1 and E2, at each of patient motion phases, 0, 1 and 2, which divided a respiration period, are prepared by using each information obtained from the detected first ?-ray. The transmission image information (T image information), T0, T1 and T2, at each of patient motion phases, 0, 1 and 2, respectively, are prepared, by using each information obtained from the detected second ?-ray. Relative displacements, ([F10], [F20]), are determined by superimposing, on T image information T0, other T image information, T1 and T2. The E image information, E1, E2, are superimposed on the E image information E0, by using this relative displacement.

Abstract: A positron emission tomography apparatus (100) includes a plurality of radiation sensitive detector systems (106) and selective trigger systems (120). The selective trigger systems identify detector signals resulting from detected gamma radiation (310) while disregarding spurious detector signals (310). In one implementation, the apparatus (100) includes a time to digital converter which decomposes a measurement time interval (Tmax) according to a binary hierarchical decomposition of level H, where H is an integer greater than equal to one.

Abstract: A method for positive emission tomography (PET) target image segmentation is provided. The method comprises capturing and digitizing image data of a selected target, determining an initial concentration ratio based on an initial source background ratio and an initial volume estimate of the selected target employing a concentration ratio table, determining a desired threshold from the initial concentration ratio and the initial volume estimate employing a threshold table, and determining a final volume estimate of the selected target based on the determined desired threshold.

Abstract: A detection unit is disclosed for arrangement in the main magnet of an MR device, which has both an RF transceiver system and a PET detector. In at least one embodiment the RF transceiver system is divided into two parts and the two parts are arranged upstream and downstream of the PET detector in the longitudinal direction of the patient tunnel. The RF transceiver system and PET detector are applied to the same image volume. In at least one other embodiment, an MR device is equipped with the detection unit, and in at least one other embodiment, a method operates the detection unit.

Abstract: A method and an apparatus are disclosed for processing of detector signals, for example in nuclear-medical imaging. In at least one disclosed embodiment, the signals from N photodetectors are transmitted to a total of approximately M=ld(N) output lines, with the signals from the photodetectors each being weighted with +1 or ?1 for the addition onto an output line.

Abstract: An image from a gamma camera, e.g., from a radiopharmaceutical, is corrected for scatter. The image is approximated by estimating the center of the organ and supposing a Guassian response that is scatter-corrected.

Abstract: A method for optimizing imaging dwell time during nuclear imaging. A fast pre-scan is conducted over the angular range of imaging, with equal dwell time at each position. A statistical sub-sampling is conducted over a region of interest to a desired fraction of the acquisition time. The statistical sub-sampling is used to simulate a varying dwell time tomographic dataset according to a profile pre-generated by an analysis of patient specific anatomic or functional information. Reconstructed data with equal dwell time and with simulated adaptive dwell time are constructed and compared to generate a difference image, a parameter of interest of which is evaluated. If the parameter of interest is within an acceptable level, the reduced dwell time for the given angular position is established; otherwise, the fraction is varied and the process is repeated. Once dwell times are computed for all view angles, a full scan is conducted.

Abstract: Detector efficiency data is generated for a positron emission tomography scanner (2) including a single photon source by conducting a blank scan acquisition procedure using the single photon source. The acquired detection count data is processed using an efficiency estimation algorithm to calculate data efficiencies of individual detectors in the detector array (8). In one embodiment, the detection count data is output as artificial coincidence count data and the efficiency estimation algorithm operates on the artificial coincidence count data. The method can be used in a non-rotating scanner or a rotating scanner.

Abstract: A detector includes a scintillator, a light guide, at least one photomultiplier, and a shield for the at least one photomultiplier. The at least one photomultiplier may be supported by a non-magnetic material. The shield includes a magnetic shield in front of the scintillator and a magnetic shield enclosing the at least one photomultiplier.

Abstract: A detector head having a small field of view, for example one which receives information from less than half a body imaged, is used to form a transmission attenuation map. The same detector head both receives information for the transmission attenuation map and also receives imaging information e.g. from a radioisotope.

Abstract: Methods and systems for controlling medical imaging are provided. A proximity sensor arrangement for an imaging system is provided. The proximity sensor arrangement includes at least one light emitter and at least one light detector. The proximity sensor arrangement further includes at least one reflector configured to reflect light waves from the at least one light emitter to the at least one light detector to form at least one light path to determine a proximity to the at least one imaging component of the imaging system.

Abstract: A method for positron emission imaging is described. A portion of an imaging subject containing a radiopharmaceutical labeled with positron emitting radionuclide is disposed between and in close proximity with a pair of gamma detectors in opposing positional relationship. Pairs of coincidence gamma rays emitted from positron annihilation events are recorded by the pair of gamma detectors. The gamma detectors are scanned over and across an area of interest of the imaging subject while their position information is recorded. The recorded gamma ray events at each scan interval are used to represent two dimensional image of positron emitting radionuclide distribution within the imaging subject.

Abstract: A positron emission tomography (PET) scanner is provided which uses information on the time-of-flight difference (TOF) between annihilation radiations for image reconstruction. The scanner has detection time correction information (memory) corresponding to information on coordinates in a radiation detection element (e.g., scintillator crystal), in the depth and lateral directions, at which an interaction has occurred between an annihilation radiation and the crystal. Reference is made to the detection time correction information, thereby providing information on time-of-flight difference with improved accuracy. As such, an improved signal to noise ratio and spatial resolution are provided for image reconstruction using time-of-flight (TOF) difference.

Abstract: The invention relates to a diagnosis device for combined or combinable radiographic and nuclear medical examinations with: an x-ray source, an examination room for accommodating a patient, a gamma radiation source arranged in the body of a patient, a detector system for simultaneously measuring the x-ray and gamma radiation without changing the patient's position. The diagnosis device implements the radiographic examination by evaluating the measurement of the x-rays and implements a single photon emission SPE examination as a nuclear examination by evaluating the gamma radiation.

Abstract: A dynamic SPECT camera is provided, comprising, a plurality of single-pixel detectors, a timing mechanism, in communication with each single-pixel detector, configured for enabling time-binning of the radioactive emissions impinging upon each single-pixel detector to time periods not greater than substantially 30 seconds, and a position-tracker, configured for providing information on the position and orientation of each detecting unit, with respect to the overall structure, substantially at all times, during the individual motion, the dynamic SPECT camera being configured for acquiring a tomographic reconstruction image of a region of interest of about 15×15×15 cubic centimeters, during an acquisition time of 30 seconds, at a spatial resolution of at least 10×10×10 cubic millimeter. The dynamic camera is configured for very short damping time, and may further acquire images in a stationary mode, with no motion.

Abstract: A device is disclosed for superposed magnetic resonance and positron emission tomography imaging. In at least one embodiment the device includes a gradient coil and a positron emission tomography unit (PET unit). The PET unit is arranged within the gradient coil and has a first shield against radiofrequency radiation which in part surrounds the PET unit, and a second shield against radiofrequency radiation is arranged on the gradient coil. The first shield is connected to the second shield to form a shield which is at least partly closed. This makes a closed shield for the PET unit possible, which nevertheless is still easily accessible for maintenance purposes due to the two-part design of the shield.

Abstract: A method for automating and extending the density range for gamma ray attenuation correction algorithms for all classes of non-destructive assay systems including those without automated shutters or automated collimators. A system and software for implementing the method are also provided. The system features a dual-intensity transmission source and utilizes a three pass scanning protocol. The high-energy source in conjunction with a beam modulator produces a high and low energy beam. Automated software determines which beam data to use in tomographic reconstruction of an object being scanned.

Abstract: An embodiment of the invention relates, in particular, to a radiation detector module for producing a radiation detector for computed tomography, having a first operating mode for quantitative and/or energy-selective detection of x-radiation. An embodiment relates to a radiation detector module including a scintillation layer for converting the x-radiation into light, and a photodetection unit for detecting the light, the photodetection unit including a multiplicity of silicon photomultipliers.