Abstract: A method and apparatus for reconstruction of a region of interest for an object is provided. The reconstruction of the object may be based on chords which may fill a part, all, or more than all of the region of interest. Using chords for reconstruction may allow for reducing data acquired and/or processing for reconstructing a substantially exact image of the ROI. Moreover, various methodologies may be used in reconstructing the image, such as backprojection-filtration, and modified filtration backprojection.

Abstract: A method and apparatus for reconstruction of a region of interest (ROI) for an object using an imaging system is provided. The imaging system may substantially exactly reconstruct the ROI with a straight line trajectory. In the straight line trajectory, the ROI is not bounded or encircled by the actual trajectory of the source (e.g., no chords that are composed from two points on the source trajectory intersect or fill the ROI to be imaged). However, the ROI may be substantially reconstructed by using “virtual” chords to reconstruct the ROI. The virtual chords are such that no point on the trajectory is included in the virtual chord (such as one that is parallel to the straight line trajectory). These virtual chords may intersect and fill the ROI, thus enabling substantially exact reconstruction. Further, in reconstructing the image, the straight line trajectory may be assumed to be infinite in length.

Abstract: A device and method used in the high resolution Positron Emission Tomography (PET) systems for digitizing radiation events for a scintillation camera and a data acquisition system. The device comprises a scintillation digitizer, including a plurality of comparators and amplifiers, two ADCs, and an analyzer for resolving the digital values of radiation events. The method comprises comparing a plurality of analog electric pulses generated upon radiation event detections with a reference voltage corresponding to an energy level of interest, amplifying all of the signals with two groups of coefficients, summing the two groups of amplified signals, digitizing the summed signals, and analyzing the digitized sums to determine digital values corresponding to a plurality of the radiation events.

Abstract: A method and apparatus are provided for reconstructing a tomographic image from fan-beam or cone-beam data. The method includes the steps of collecting fan-beam or cone-beam data over an image space, converting the fan-beam or cone-beam data to parallel-beam data with respect to a rotation angle within the image space, performing a shift variant filtration of the parallel-beam data within the image space and converting the processed data to images through backprojection or other means.

Abstract: A device and method used in high resolution positron emission tomography (PET) systems for digitizing gamma ray energy and characterizing peak time and decay time constant, models a voltage pulse generated upon a PET event detection as a fast linearly rising edge followed by a slower exponential decay. The model includes parameters of the voltage pulse that are relevant for PET event detection including a decay constant, a peak voltage value, and a peak time, which are determined from time interval measurements of the voltage pulse. The time interval measurements are made using comparators and counters in an exemplary electronic implementation.

Abstract: A method and apparatus for reconstruction of a region of interest for an object is provided. The reconstruction of the object may be based on chords which may fill a part, all, or more than all of the region of interest. Using chords for reconstruction may allow for reducing data acquired and/or processing for reconstructing a substantially exact image of the ROI. Moreover, various methodologies may be used in reconstructing the image, such as backprojection-filtration, and modified filtration backprojection.

Abstract: A device and method used in the high resolution Positron Emission Tomography (PET) systems for digitizing radiation events for a scintillation camera and a data acquisition system. The device comprises a scintillation digitizer, including a plurality of comparators and amplifiers, two ADCs, and an analyzer for resolving the digital values of radiation events. The method comprises comparing a plurality of analog electric pulses generated upon radiation event detections with a reference voltage corresponding to an energy level of interest, amplifying all of the signals with two groups of coefficients, summing the two groups of amplified signals, digitizing the summed signals, and analyzing the digitized sums to determine digital values corresponding to a plurality of the radiation events.

Abstract: A device and method used in high resolution positron emission tomography (PET) systems for digitizing gamma ray energy and characterizing peak time and decay time constant, models a voltage pulse generated upon a PET event detection as a fast linearly rising edge followed by a slower exponential decay. The model includes parameters of the voltage pulse that are relevant for PET event detection including a decay constant, a peak voltage value, and a peak time, which are determined from time interval measurements of the voltage pulse. The time interval measurements are made using comparators and counters in an exemplary electronic implementation.

Abstract: A method and apparatus are provided for reconstructing images from data obtained from scintillation events occurring within a projection space of a depth-of-interaction positron emission tomography system. The method includes the steps of identifying a segment of each depth-of-interaction detector of respective pairs of depth-of-interaction detectors detecting the scintillation-events of the data obtained within the projection space and estimating a set of sinograms from the data based upon a set of depth-independent point spread functions of the identified segments of the respective pairs of depth-of-interaction detectors.