Abstract: According to one embodiment, a TOF-PET apparatus includes a plurality of detector rings arranged along a central axis thereof. Each of the detector rings comprises a plurality of scintillators and a plurality of photomultipliers. The scintillators are arranged on a substantial circumference around the central axis and generate scintillation in response to pair annihilation gamma-rays from a subject. The photomultipliers generate an electric signal in accordance with the generated scintillation. A length of each of the scintillators along a radial direction of the substantial circumference is set to a range in which a value of a total number of counts/time resolution of coincidence events of pair annihilation gamma-rays is more improved than when a reference scintillator whose probability of interaction with pair annihilation gamma-rays is adjusted to 80% is used under conditions of a constant total volume of the scintillators.

Abstract: An imaging system includes a platform having mounted thereon an imaging device. The imaging device includes a first detector and a second detector. The imaging system includes a mask having a first pattern of apertures therein, the mask positioned on a first side of the first detector, an anti-mask having a second pattern of apertures therein, wherein the second pattern is derived from the first pattern, the anti-mask positioned on a first side of the second detector, and a computer configured to acquire a plurality of mask datasets and anti-mask datasets of a gamma source, add one of the mask datasets and subtract its respective anti-mask dataset to create a far-field dataset, adjust the far-field image dataset, reconstruct a near-field image of the source using the far-field dataset, and apply an expectation maximization (EM) algorithm to one of the far-field image dataset and the near-field image to enhance contrast.

Abstract: A method is disclosed for determining radiation attenuation by an examination object in a positron emission tomography scanner. In at least one embodiment of the method, an initial segmentation of the examination object is fixed, wherein an attenuation coefficient is assigned to each segment of the segmentation. Furthermore, raw radiation data about the examination object arranged in the positron emission tomography scanner is acquired, and a correction factor is automatically determined for each pixel with the aid of an optimization method, in which the probability of the acquired raw radiation data is maximized taking into account the segmentation and the attenuation coefficients assigned to the segments. A statistical parameter of the correction factors is then determined for each segment and the segmentation is corrected by subdividing a segment as a function of the statistical parameter determined for the segment.

Abstract: A method is described for acquiring and analysing the data produced by Positron Emission Tomography (PET), which method provides for an accurate estimation of vascular compartment volume, VB. An MRI scan and the PET scan is performed simultaneously and the results of the former is used to derive a value for VB. The value so derived is then used in pharmacokinetic modelling along with the results of the functional scan.

Abstract: Methods and systems for performing a patient scan using a three-dimensional (3D) cylindrical Positron Emission Tomography (PET) imaging system are provided. The method includes acquiring a count-rate profile of a brain, repositioning at least one of a detector and the brain based on the count-rate profile and a detector sensitivity profile, and scanning the brain when the acquired count-rate profile substantially matches the detector sensitivity profile.

Abstract: In a nuclear medicine imaging apparatus as a medical image diagnosis apparatus according to one embodiment, a PET detector is configured to detect a gamma ray emitted from a nuclide introduced into a body of a subject. A PET image reconstruction unit is configured to reconstruct a nuclear medicine image (PET image) as a medical image from the gamma ray projection data created based on the gamma ray detected by the PET detector using successive approximation. A controller is configured to control the PET image reconstruction unit to change the parameter used in the successive approximation depending on information regarding the scanning region in the body of the subject.

Abstract: A nuclear medicine imaging apparatus according to an embodiment includes a gradation width storage, an estimating unit, and an image generating unit. The gradation width storage is configured to store the gradation width of an image determined by the temporal resolution of a detector. The estimating unit is configured to estimate the spatial position of a positron on the basis of the spatial position of a set of detectors and a set of detection times. The image generating unit is configured to allocate pixel value to pixels corresponding to the gradation width around the estimated spatial position such that a spatial resolution corresponding to the temporal resolution is reflected on a line linking the set of detectors, thereby generating an image.

Abstract: A nuclear medicine imaging apparatus according to an embodiment of the invention includes a detector, a measuring unit, and an end control unit. The detector is configured to detect radiation for generating a nuclear medicine image. The measuring unit is configured to measure the number of times the detector detects the radiation. The end control unit is configured to control the detector to end the detection operation when the number of times measured by the measuring unit is equal to or less than a threshold value.

Abstract: An RF antenna arrangement of a combined MR/PET system is disclosed. In at least one embodiment, the RF antenna arrangement includes a first part installed in the examination tunnel in a fashion fixed to the system such that it is arranged underneath the couch board when the latter is introduced, and a second part, which can be placed onto the couch board and be introduced into and withdrawn from the examination tunnel together with the couch board. In at least one embodiment, the second part is of dimensionally stable design and has a clear cross section that is adapted to the object to be examined. Consequently, the time outlay for applying the RF antenna is reduced, and the fixed position of the RF antenna enables a correction of the attenuation of gamma rays. Furthermore, a number of second parts having various diameters can be provided.

Abstract: A system is provided for obtaining a nuclear image of a moving object. The system comprises an input (14), a processing unit (15) and an output (17). The input (14) is provided for receiving a nuclear image and morphological images of the object. The processing unit (15) is configured to process the morphological images to obtain sparse motion information of the object, to use the sparse motion information and a motion model for obtaining estimated motion information about the object, and to generate a motion-corrected nuclear image based on the estimated motion information and the acquired nuclear image. The output (17) provides the corrected nuclear image.

Abstract: A method for improving clinical data quality in Positron Emission Tomography (PET). The method provides for the processing of PET data to accurately and efficiently determine a data signal-to-noise (SNR) corresponding to each individual clinical patient scan, as a function of a singles rate in a PET scanner. The method relates an injected dose to the singles rate to determine SNR(Dinj), and provides an accurate estimate of quantity proportional to SNR, similar in function to SNR(Dinj). Knowledge of SNR(Dinj) permits determination of peak SNR, optimal dose, SNR deficit, dose deficit, and differential dose benefit. The patient dose is fractionated, with a small calibration dose given initially. After a short uptake, the patient is pre-scanned to determine T, S, and R. An optimal dose is then determined and the remainder is injected.

Abstract: An apparatus and method to increase the sensitivity at the edge of radiation detector blocks is disclosed herein. Reduced sensitivity can result from photons entering a first detector block, escaping, and scattering into an adjacent detector, thereby depositing energy into two detectors blocks. Energy lost into adjacent detector blocks can be compensated with energy detected in the adjacent detector block. This can be done, for example, by processing channels from multiple detector blocks with one Field Programmable Gated Array (FPGA) on one Event Process Module (EPM) board. This can enable summing energy of one detector block with energy from an adjacent detector block when the initial interaction occurs at the edge of the first detector block. This can result in a better estimate of the amount of energy associated with the initial photon being detected.

Abstract: The invention concerns an optical weighing method for measuring a DOI by-estimating the position (X) at the time of impact of a gamma photon in a crystalline medium, which has a juxtaposition of sections between which are created the conditions for a discrete energy loss of known magnitude, and wherein is compared the energy (E1; E2) collected by photodetectors (4,-5), mounted at longitudinal ends (2; 3) of said medium for estimating said position (X) in a given segment. The invention concerns a device including a photon detecting bar (1) including a single crystal extending along a longitudinal direction, including photodetectors at each end on flat surfaces perpendicular to said direction, It is characterized in that it includes a succession of single-crystalline bar lengths, homogeneous, isotropic and full, separated by dioptric mediums and/or openings parallel with said flat surfaces.

Abstract: A PET scanner (8) includes a ring of detector modules (10) encircling an imaging region (12). Each of the detector modules includes at least one detector pixel (24,34). Each detector pixel includes a scintillator (20, 30) optically coupled to one or more sensor APDs (54) that are biased in a breakdown region in a Geiger mode. The sensor APDs output a pulse in response to the light from the scintillator corresponding to a single incident radiation photon. A reference APD (26, 36) also biased in a break-down down region in a Geiger mode is optically shielded from light and outputs a temperature dependent signal. At least one temperature compensation circuit (40) adjusts a bias voltage applied to the sensor APDs based on the temperature dependent signal.

Abstract: When detecting scintillation events in a nuclear imaging system, time-stamping and energy-gating processing is incorporated into autonomous detection modules (ADM) (14) to reduce downstream processing. Each ADM (14) is removably coupled to a detector fixture (13), and comprises a scintillation crystal array (66) and associated light detect or (s) (64), such as a silicon photomultiplier or the like. The light detector(s) (64) is coupled to a processing module (62) in or on the ADM (14), which performs the energy gating and time-stamping.

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 method for reducing randoms variance in a Positron Emission Tomograph (PET) or Positron Emission Tomograph combined with another Medical Imaging device is disclosed. An average of an element of the randoms event (delayeds) sinogram may be estimated by dividing fan sums in delayeds sinogram by singles rates taken from headers of the delayeds sinogram.

Abstract: Large-area, flat-panel photo-detectors with sub-nanosecond time resolution based on microchannel plates are provided. The large-area, flat-panel photo-detectors enable the economic construction of sampling calorimeters with, for example, enhanced capability to measure local energy deposition, depth-of-interaction, time-of-flight, and/or directionality of showers. In certain embodiments, sub-nanosecond timing resolution supplies correlated position and time measurements over large areas. The use of thin flat-panel viewing radiators on both sides of a radiation-creating medium allows simultaneous measurement of Cherenkov and scintillation radiation in each layer of the calorimeter. The detectors may be used in a variety of applications including, for example, medical imaging, security, and particle and nuclear physics.

Abstract: Improved processing electronic hardware are disclosed that facilitate the efficient processing of PET system data, while enhancing accuracy and compatibility of PET systems with other analytical methods (e.g., magnetic resonance imaging).

Abstract: A single crystal scintillator material according to the present invention includes a single crystal portion that is represented by the compositional formula (CexLu1-x)BO3 in which the mole fraction x of Ce satisfies 0.0001?x?0.05.

Abstract: A region of interest is automatically evaluated. The automatic evaluation is based on assessments of one or more characteristics. The one or more characteristics of the region of interest are assessed in a plurality of image data sets acquired by a respective plurality of imaging modalities. In some embodiments, the evaluation is based on assessments of one or more characteristics for each region of interest derived from a combination of structural and functional image data. In one embodiment, the set of structural image data is a set of CT image data and the set of functional image data is a set of PET image data. The one or more lesions may be detected in the structural and/or functional image data by automated routines or by a visual inspection by a clinician or other reviewer.

Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A parameterized ideal curve shape is selected to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, a curve from the parameterized ideal curve shape is selected, that best represents the received analog pulse signal, and the selected curve is used to estimate the pulse start time.

Abstract: A PET instrument free from problems of maintenance of a detector when a field of view in a body axial direction of a subject is significantly enlarged. A gantry (1) is divided into a plurality of units (5) in the body axial direction of the subject. Each unit (5) is configured to be movable in an orthogonal direction to the body axial direction. Further, a number of detectors are provided in each unit (5) and arranged in its circumferential direction and the body axial direction.

Abstract: A system and method is provided for determining depth of interaction (DOI) information. The system and method includes a detector configured to generate DOI information as a result of radiation emitted from a radiation source. The system and method further includes a plurality of scintillator pixels forming a block, wherein the plurality of scintillator pixels have a first portion and a second portion. A first medium distributed in an alternating pattern of coupling and separation between each of the scintillator pixels in a first portion or second portion of the block is also provided. A plurality of sensors for detecting scintillation events across the plurality of scintillators based on the alternating pattern of coupling and separation between each of the scintillator pixels, wherein DOI information is provided by a position profile of the block, and an image processor for generating a 3 dimensional image from the DOI information are also included.

Abstract: A host lattice modified GOS scintillating material and a method for using a host lattice modified GOS scintillating material is provided. The host lattice modified GOS scintillating material has a shorter afterglow than conventional GOS scintillating material. In addition, a radiation detector and an imaging device incorporating a host lattice modified GOS scintillating material are provided.

Abstract: When employing hygroscopic scintillation crystals (32) in a nuclear detector (e.g., PET or SPECT), Silicon photo-multiplier (SiPM) sensors (34) are coupled to each scintillation crystal (32) to improve scintillation event detection and reduce scatter. The crystals (32) and sensors (34) are hermetically sealed in a detector housing (50) using a sealant layer (51). Electrical contacts (60) from each sensor (34) extend through the sealant layer (51) or are bused together such that the bus extends through the sealant layer (51). In this manner, hygroscopic scintillation crystals (e.g., LaBr, NaI, etc.) are protected from humidity and light scatter is reduced by direct coupling of the sensors (34) and crystals (32).

Abstract: A compound comprising a metal chelate linked to a hexose carrier for use as a metallopharmaceutical diagnostic or therapeutic agent is provided. The compound is suitable for imaging by single-photon emission computed tomography, computer assisted tomography, magnetic resonance spectroscopy, magnetic resonance imaging, positron emission tomography, fluorescence imaging or x-ray.

Abstract: According to one embodiment, a nuclear medicine diagnosis includes a light signal generating unit, photodetection unit, measurement unit, calculation unit, and storage unit. The light signal generating unit repeatedly generates light signals. The photodetection unit repeatedly generates first output signals corresponding to intensities of the light signals, repeatedly generates second output signals corresponding to intensities of gamma rays emitted from a subject. The measurement unit repeatedly measures light signal detection times and repeatedly measures gamma ray detection times. The calculation unit calculates a difference between a target gamma ray detection time and a target light signal detection time of the light signal detection times for each of the gamma ray detection times. The target light signal detection time is measured before the target gamma ray detection time. The storage unit stores the calculated difference in association with a target second output signal of the second output signals.

Abstract: An apparatus and associated method for gamma ray detection that improves the timing resolution is provided. A crystal of interaction in a scintillation crystal array emits scintillation light in response to interaction with a gamma ray. The scintillation light is detected by one or more photomultiplier tubes. Each photomultiplier tube that detects the scintillation light detects the light at a different time. The apparatus determines the location of the gamma ray interaction and uses the location of the interaction to generate correction times for each waveform generated by the photomultiplier tubes. The waveforms are corrected with the correction timings and combined to extract a time of arrival estimate for the gamma ray. Noise thresholding is also used to select waveforms having low noise for combination to extract the time of arrival estimate.

Abstract: Methods and systems for producing an image. A measurement is obtained, and a projector function is generated using the obtained measurement. The generated projector function is modified based on an a priori image. An image is reconstructed using the modified projector function.

Abstract: Whether a phenomenon of photon incidence on detectors is a double event or a single event is determined (step S1). When it is a double event, emission data is collected (S2), and is put to an image reconstruction process (S3). When it is a single event, on the other hand, the data is collected as data for calibration (S4), and is put to a calibration process (S5). Since the data for calibration is collected during a clinical practice, a PET apparatus can be calibrated frequently without lowering the operating ratio of the apparatus.

Abstract: A tungstate-based scintillating material and a method for using a tungstate-based scintillating material is provided. In addition, a radiation detector and an imaging device incorporating a tungstate-based scintillating material are provided.

Abstract: An imaging method and apparatus, the method comprising collecting detector output data from a radiation detector positioned near a subject provided with a radio-active tracer, and resolving individual signals in the detector output data by (i) determining a signal form of signals present in the data, (ii) making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least a signal temporal position, and (iii) determining the energy of each of the signals from at least the signal form and the parameter estimates. The acceptable subject to detector distance is reduced or increased, spatial resolution is improved, tracer dose or concentration is reduced, subject radiation exposure is reduced and/or scanning time is reduced.

Abstract: A PET apparatus comprises a plurality of detector units in the circumferential direction, wherein the detector unit includes a plurality of unit substrates therein, and wherein the unit substrate includes: a plurality of detectors upon which a ?-ray is incident; and an analog ASIC and digital ASIC for processing a ?-ray detection signal outputted by each of the detectors. The analog ASIC includes two slow systems having mutually different time constants, each of which outputs a pulseheight value. A noise determination part of the digital ASIC determines whether a relevant detection signal is an intended ?-ray detection signal or a noise based on a correlation between the pulseheight values, and a noise counting part counts the number of times of noise determination, and a detector output signal processing control part controls the signal processing with respect to an output signal from a relevant detector based on the count.

Abstract: A radiation detector includes an array of detector pixels each including an array of detector cells. Each detector cell includes a photodiode biased in a breakdown region and digital circuitry coupled with the photodiode and configured to output a first digital value in a quiescent state and a second digital value responsive to photon detection by the photodiode. Digital triggering circuitry is configured to output a trigger signal indicative of a start of an integration time period responsive to a selected number of one or more of the detector cells transitioning from the first digital value to the second digital value. Readout digital circuitry accumulates a count of a number of transitions of detector cells of the array of detector cells from the first digital state to the second digital state over the integration time period.

Abstract: Methods and systems for performing a patient scan using a three-dimensional (3D) cylindrical Positron Emission Tomography (PET) imaging system are provided. The method includes acquiring a count-rate profile of a brain, repositioning at least one of a detector and the brain based on the count-rate profile and a detector sensitivity profile, and scanning the brain when the acquired count-rate profile substantially matches the detector sensitivity profile.

Abstract: A gamma ray detector for detecting a gamma ray emitted from a target of measurement includes: an organic scintillator for detecting Compton electrons resulting from a gamma ray emitted from the target of measurement; an inorganic scintillator for detecting a Compton gamma ray; and photodetector modules for detecting light generation in the corresponding scintillators. Light generation signals from the organic and inorganic scintillators are synchronously measured, and a detection window of a gamma ray is generated. Thus, an inexpensive radiation diagnostic device of an ultra-high S/N ratio and low cost is provided.

Abstract: The invention provides CTGF which is associated with the cardiovascular diseases and hematological diseases. The invention also provides assays for the identification of compounds useful in the treatment or prevention of cardiovascular diseases and hematological diseases. The invention also features compounds which bind to and/or activate or inhibit the activity of CTGF as well as pharmaceutical compositions comprising such compounds.

Abstract: In beam monitoring for detecting annihilation radiations produced by radiation irradiation in radiation therapy for cancer which is performed by irradiating the affected area by X-rays, gamma rays, or particle beams, a detector-shift type combined radiation therapy/PET apparatus is provided with an open PET device that includes a plurality of shiftable multi-ring detector rings; and a radiation irradiation device that is capable of irradiation with a radiation beam through between the detector rings. The apparatus changes the positions of the detector rings, performs irradiation with the radiation beam through between the detector rings, and then performs radiation measurement.

Abstract: During data acquisition in a tomographic scan of a subject unscattered events and scatter events are collected. The data are corrected for the scatter events and movement of the subject during the scan. A scatter estimate is derived for use in the reconstruction of an image of the subject; a first step in the derivation has a first dependence on the movement of the subject. The image of the subject is derived from the detected events using the scatter estimate; a second step in this derivation has a second dependence on the movement of the subject, the dependence being different from that of the first step.

Abstract: A radiological imaging method comprises: acquiring radiological lines of response (LOR's) from a subject; grouping the acquired LOR's into time intervals such that each group of LOR's (20) was acquired during a selected time interval; identifying a region of interest (60, 74) for each time interval based on LOR's grouped into that time interval; for each time interval, determining a positional characteristic (102) of the region of interest identified for that time interval based on LOR's grouped into that time interval; for each time interval, spatially adjusting LOR's grouped into that time interval based on the positional characteristic of the region of interest identified for that time interval; and reconstructing at least the spatially adjusted LOR's to generate a motion compensated reconstructed image.

Abstract: A method of processing positron emission tomography (PET) information obtained from a PET detector having a plurality of detector regions, each detector region having at least one detector module and a corresponding regional collector, the method including the steps of receiving PET event information for a single PET event, the PET event information including energy information and crystal position information of the single PET event; receiving non-detector event information; generating an event list that includes (1) a PET event entry, the PET event entry including a fine time stamp, the energy information, and the crystal position information, and (2) a non-detector event entry that includes the received non-detector event information; and transmitting the generated event list to a computer for off-line processing.

Abstract: A positron emission tomography (PET) scanner system, including a detector that acquires PET event information, the detector being configured to move during acquisition of the PET event information; a first motion unit that acquires first event information of a position of a patient bed, the patient bed being configured to move during acquisition of the PET event information; a second motion unit that acquires second event information of the detector; an event collector that generates an event list of events that includes the PET event information, the first event information, and the second event information; and a list-mode reconstructing unit that reconstructs an image by processing the generated event list.

Abstract: A method and system for automatically gating an imaging device is disclosed. Physiological process information of a patient may be derived from a plethysmographic signal, for example, by analyzing the plethysmographic signal transformed by a continuous wavelet transform. Other techniques for deriving physiological process information of a patient include, for example, analyzing a scalogram derived from the continuous wavelet transform. The physiological process information may be used to automatically gate imaging data acquired from an imaging device in order to synchronize the imaging data with the physiological process information.

Abstract: A positron emission tomography detector module that includes an array of optically isolated crystal elements and photomultiplier tubes that receive light emitted from the array of crystal elements and are arranged to cover the array of crystal elements. The photomultiplier tubes include photomultiplier tubes having two different sizes arranged in various patterns that minimize the number of edges. The axial extent of each detector module is at least three times longer than the other axis of the detector module.

Abstract: In a time-of-flight positron emission tomography (TOF-PET) imaging method, three-dimensional time-of-flight line-of-response (TOF-LOR) data are acquired. Each TOF-LOR corresponds to a line-of-response with time-of-flight spatial localization. The TOF-LOR data are slice-binned into a plurality of two-dimensional TOF-LOR data sets based on the time-of-flight spatial localization. At least some of the slice-binned TOF-LOR data correspond to lines of response that are oblique to the two-dimensional data sets. The TOF-LOR data are coarsely angularly rebinned to a plurality of coarse angular bins each having an angular span of at least about 10°. The coarsely angularly binned TOF-LOR data are reconstructed to produce the image slice.

Abstract: The present invention provides a method for estimating crystal efficiency in a PET detector that takes axial compression into account. It does so via an iterative methodology in which a ?-map is first generated and then is used to obtain a solution for the equation L ? ( ? i ) = ? n ? N ? ? y n ? log ? ? i , j ? span ? ? g ij ? ? i ? ? j ? x ij - ? i , j ? span ? ? g ij ? ? i ? ? j ? x ij , wherein gij is a geometric factor for LOR(i,j), ?i and ?j are the efficiencies for crystal i and crystal j, and xij is the line integral of the source distribution along LOR(i,j). Once efficiencies are determined, they are used to calibrate the PET detector.

Abstract: In an open-type PET scanner including a plurality of detector rings having multiple rings arrayed in the body axis direction, radiation measurement is performed while at least one detector ring is relatively moved with respect to a subject in the body axis direction, thereby dispersing simultaneous radiation in an open region to suppress a local reduction in sensitivity. The detector rings are optimized in constitution, moving direction and/or moving speed, thus making it possible to reduce the variation of distribution of sensitivity and expand a clearance in the open region and a field-of-view in the body axis direction.

Abstract: A detection module for detecting electro-magnetic radiation comprises a photosensor, a current integration circuit and an arithmetic unit fits the integration samples to a predetermined time dependency of the integrated current and computes an accumulated electrical charge accumulated over the integration time interval from the fit. Notably, the detection module is employed in an optical imaging apparatus to image e.g. a woman's breast by way of near-infrared light.

Abstract: When performing positron emission tomography (PET) scanning and image reconstruction, a primary PET system (10) with a primary PET detector array (12) is used to image a patient or subject, and a secondary PET detector array (14) is coupled to the system at specific input points to mitigate unnecessary duplication of system components. The primary system (10) provides PET data processing and reconstruction for the secondary array (14), in addition to the first array (12). An adjustable array (120) includes radially movable detectors (122) and stationary detectors (124) with different crystal resolutions. The movable detectors (122) are alternately positioned with the stationary detectors (124) at a first radius to form a large detector ring, or are positioned at a second, smaller radius without the stationary detectors (124) to form a small detector ring.