Abstract: Methods and systems are provided for interpolating acquired data of a tracer distribution. In one embodiment, a method comprises reconstructing the acquired data, and interpolating the reconstructed data with a surface, wherein a slope of the surface at a data point of the reconstructed data is limited by a value of the data point. In this way, interpolation artifacts around objects with high tracer density may be avoided.

Abstract: Methods and systems are provided for interpolating acquired data of a tracer distribution. In one embodiment, a method comprises reconstructing the acquired data, and interpolating the reconstructed data with a surface, wherein a slope of the surface at a data point of the reconstructed data is limited by a value of the data point. In this way, interpolation artifacts around objects with high tracer density may be avoided.

Abstract: A method for enhancing contrast in fluorescence imaging is provided. The method comprises providing a patterned illumination source for illuminating one or more regions corresponding to a scan step, scanning at least a portion of a surface of a subject using a plurality of scan steps, acquiring image frames corresponding to two or more scan steps, deducting a background fluorescence from the image frames corresponding to the two or more scan steps to form one or more processed image frames, and reconstructing an image using one or more of the processed image frames.

Abstract: The present disclosure relates to the correction of charge loss in a radiation detector. In one embodiment, correction factors for charge loss may be determined based on depth of interaction and lateral position within a radiation detector of a charge creating event. The correction factors may be applied to subsequently measured signals to correct for the occurrence of charge loss in the measured signals.

Abstract: Nuclear imaging systems, non-transitory computer readable media and methods for tomographic imaging are presented. Projection data is acquired by scanning one or more views of a subject for a designated scan interval less than a total scan interval. A first image of a target region of interest (ROI) is reconstructed using projection data acquired over a first fraction of the designated scan interval. A second target ROI image is reconstructed using at least a subset of projection data acquired over the first and/or a second fraction. A change in an image quality characteristic over the first and the second fractions is determined by determining one or more differences between the first and the second images. A value of an imaging parameter is estimated based on the change to acquire projection data for generating a target ROI image having at least a predetermined level of the image quality characteristic.

Abstract: A method for enhancing contrast in fluorescence imaging is provided. The method comprises providing a patterned illumination source for illuminating one or more regions corresponding to a scan step, scanning at least a portion of a surface of a subject using a plurality of scan steps, acquiring image frames corresponding to two or more scan steps, deducting a background fluorescence from the image frames corresponding to the two or more scan steps to form one or more processed image frames, and reconstructing an image using one or more of the processed image frames.

Abstract: An apparatus and methods for evaluating the operation of pixelated detectors are provided. The method includes obtaining data values for each of a plurality of pixels of a pixelated detector and determining a data consistency metric for each of the plurality of detector pixels. The method further includes identifying, using the determined data consistency metric, any detector pixels that exceed an acceptance criterion as noisy pixels.

Abstract: The present disclosure relates to the correction of charge loss in a radiation detector. In one embodiment, correction factors for charge loss may be determined based on depth of interaction and lateral position within a radiation detector of a charge creating event. The correction factors may be applied to subsequently measured signals to correct for the occurrence of charge loss in the measured signals.

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 detector for identification and localization of radioisotopes, comprising a position sensitive detector configured to observe the location of emitted high energy radiation, wherein the position sensitive detector comprises a surface comprised of a first radiation sensitive material; and an active mask disposed in front of the position sensitive detector positioned such that the emitted high energy radiation is detected by the position sensitive detector after passage through the mask, wherein the mask comprises a second radiation sensitive material.

Abstract: Apparatus and methods for determining a system matrix for pinhole collimator imaging systems are provided. One method includes using a closed form expression to determine a penetration term for a collimator of the medical imaging system and determining a point spread function of the collimator based on the penetration term. The method further includes calculating the system matrix for the medical imaging system based on the determined point spread function.

Abstract: Apparatus and methods for determining a system matrix for pinhole collimator imaging systems are provided. One method includes using a closed form expression to determine a penetration term for a collimator of the medical imaging system and determining a point spread function of the collimator based on the penetration term. The method further includes calculating the system matrix for the medical imaging system based on the determined point spread function.

Abstract: An apparatus and methods for evaluating the operation of pixelated detectors are provided. The method includes obtaining data values for each of a plurality of pixels of a pixelated detector and determining a data consistency metric for each of the plurality of detector pixels. The method further includes identifying, using the determined data consistency metric, any detector pixels that exceed an acceptance criterion as noisy pixels.

Abstract: A detector for identification and localization of radioisotopes, comprising a position sensitive detector configured to observe the location of emitted high energy radiation, wherein the position sensitive detector comprises a surface comprised of a first radiation sensitive material; and an active mask disposed in front of the position sensitive detector positioned such that the emitted high energy radiation is detected by the position sensitive detector after passage through the mask, wherein the mask comprises a second radiation sensitive material.

Abstract: A method and system for calibrating a time of flight (TOF) positron emission tomography (PET) scanner are provided. The method stores acquired scan data from detector pairs including data and timing information. The method further calculates an intensity distribution of emission sources based on the scan data and defines a timing pivot point based on a median of an intensity histogram. The method determines a timing correction for each detector based on the location of the timing pivot point. The positron emission tomography (PET) system further provides a plurality of detectors, used in performing imaging scans, and a processor. The processor is configured to determine a timing correction for each detector.

Abstract: The invention is directed to a technique for reconstructing PET scan images. According to one embodiment, the invention relates to a method for reconstructing PET scan images. The method comprises: detecting a plurality of coincidence events in a PET scanner; storing data associated with the plurality of coincidence events in a chronological list based on a detection time for each of the plurality of coincidence events; generating correction data based on scatter coincidence events and random coincidence events in the plurality of coincidence events; and reconstructing one or more PET scan images based at least in part on the chronological list of data and the correction data.

Abstract: A technique is provided for imaging based on localization of fluorescence in a medium. The technique includes illuminating the medium with an excitation light to excite fluorescence, scanning the medium at a plurality of locations via an ultrasonic beam, modulating a portion of the emitted light from the fluorescence via the ultrasonic beam at each of the plurality of locations, differentially detecting the modulated light at a boundary of the medium, and reconstructing an image from the detected signal.

Abstract: A method for detecting radiation using a monolithic detector is provided. The method includes providing a monolithic scintillator to interact with incident radiation and to generate a photon at a site of interaction, optically coupling a plurality of photosensors to the monolithic scintillator to detect the photon generated at the site of interaction, and configuring each photosensor to transmit a signal indicative of an amount of light detected by each photosensor and a solid angle covered by the photosensor relative to the site of interaction.

Abstract: A detector including opposed detector heads having anode signal processors which perform a sliding box car integration of each PMT anode signal, corrects for baseline shifts and pileup from the tails of previous events, vary the length of the box car based on the time between events, and use a peak detection circuit to reduce the dependence of the integrated value on timing differences between the asynchronous events and the synchronous ADC conversion is described. The outputs of anode processors are combined to provide the X and Y coordinates, and the energy E, of an event. The outputs from each head processor are then combined in a coincidence processor to provide the corrected positions and energies of coincidence events. The above described detector heads function at a high count rate with minimum dead time and pileup.