Abstract: A method of sensing radionuclides in cells is provided that includes exposing a cell of interest to a radiolabeled molecule, encapsulating the cell of interest with a chemical sensor in an encapsulant to hold the cell of interest and the chemical sensor in proximity, where the radiolabeled molecule decays to emit an energetic particle, and detecting a fluorescence or optical absorption signal in the chemical sensor induced by the radio molecule decay, using an illumination source and a detector, where single-cell analysis with the radiolabeled molecule is performed.

Abstract: A method of reconstructing time-varying position of individual radioactive point sources directly from Positron Emission Tomography (PET) measurements is provided that includes using a PET scanner to acquire list-mode coincidence events of a moving radioactive point source, using an appropriately programmed computer to model a trajectory of the moving radioactive point source as a 3D function of a temporal variable, then apply an optimization procedure to find the trajectory that minimizes a distance between the trajectory and the recorded list-mode coincidence events, and using the PET scanner to output a real time position of the radioactive point source.

Abstract: Molecular imaging of radioluminescent nanoparticle probes injected into biological tissue is performed by irradiated the tissue with ionizing radiation to induce radioluminescence at optical wavelengths, preferably at predetermined near infrared wavelengths. The optical light is detected and processed to determine a spatial distribution of the probes. The radioluminescent nanoparticles may be inorganic or organic phosphors, scintillators, or quantum dots. Imaging systems realizing this technique include tomographic systems using an x-ray beam to sequentially irradiate selected regions, systems with a radioactive source producing the ionizing radiation from outside the tissue, such as with a beam, or inside the tissue, such as with an endoscope or injected radiopharmaceutical.

Abstract: A method of sensing radionuclides in cells is provided that includes exposing a cell of interest to a radiolabeled molecule, encapsulating the cell of interest with a chemical sensor in an encapsulant to hold the cell of interest and the chemical sensor in proximity, where the radiolabeled molecule decays to emit an energetic particle, and detecting a fluorescence or optical absorption signal in the chemical sensor induced by the radio molecule decay, using an illumination source and a detector, where single-cell analysis with the radiolabeled molecule is performed.

Abstract: A method of reconstructing time-varying position of individual radioactive point sources directly from Positron Emission Tomography (PET) measurements is provided that includes using a PET scanner to acquire list-mode coincidence events of a moving radioactive point source, using an appropriately programmed computer to model a trajectory of the moving radioactive point source as a 3D function of a temporal variable, then apply an optimization procedure to find the trajectory that minimizes a distance between the trajectory and the recorded list-mode coincidence events, and using the PET scanner to output a real time position of the radioactive point source.

Abstract: Line segments are classified according to orientation to improve list mode reconstruction of tomography data using graphics processing units (GPUs). The new approach addresses challenges which include compute thread divergence and random memory access by exploiting GPU capabilities such as shared memory and atomic operations. The benefits of the GPU implementation are compared with a reference CPU-based code. When applied to positron emission tomography (PET) image reconstruction, the GPU implementation is 43× faster, and images are virtually identical. In particular, the deviation between the GPU and the CPU implementation is less than 0.08% (RMS) after five iterations of the reconstruction algorithm, which is of negligible consequence in typical clinical applications.

Abstract: A radioluminescence microscopy system and method for imaging the distribution of radiolabeled molecules in live cell cultures and tissue sections. Cells are grown and incubated with radiolabeled molecules on a scintillator plate or a scintillator plate is placed adjacent to the cells after incubation. Scintillation light produced by decay of radiolabeled molecules inside, bound to, or surrounding the cells, is recorded on an imaging device. Fluorescence microscopy of the same cells with other types of molecules of interest that are labeled with different fluorophores can be conducted concurrently and the biological activity of the labeled molecules can be correlated.

Abstract: The present invention provides a method of reconstructing a tomographic image. In a first step, a tomographic image is forward-projected along a list of geometrical lines in a GPU. This list of geometrical lines may be list-mode event data acquired from a tomographic scanner. Alternatively, the list may be a list of weighted lines derived from a sinogram, a histogram, or a timogram acquired from a tomographic scanner. Next, the list of geometrical lines is back-projected into a 3-dimensional volume using the GPU. The results of the forward- and back-projection are then used to reconstruct the tomographic image, which is then provided as an output, e.g. to make the image available for further processing. Examples of output include storage on a storage medium and display on a display device.

Abstract: Methods and systems for determining a sequence of energy interactions in a detector. A plurality of discrete energy interactions is received in a plurality of detector voxels. A plurality of possible sequences of interaction is formed based on the received plurality of discrete energy interactions. For each of the plurality of possible sequences of interaction, an a posteriori probability is computed, where the a posteriori probability is based on a likelihood that the possible sequence of interaction is consistent with the received plurality of discrete energy interactions. Additionally or alternatively, the a posteriori probability may be based on an a priori probability. One of the formed plurality of possible sequences of interaction is selected based on the computed a posteriori probability.

Abstract: A method of characterizing a tissue sample is provided that includes injecting a tissue sample with radiotracers, where the radiotracers include beta-emitter radio tracers, the beta-emitter radio tracers emit beta particles according to a decay of the beta-emitter radio tracers, and measuring the beta particles or Cherenkov radiation from the beta particles in the tissue sample, and determining a condition of the radio tracers in the tissue sample according to the measured beta particles or the measured Cherenkov radiation, where the determined condition includes a depth and/or a concentration of the radiotracers in the tissue sample.

Abstract: Molecular imaging of radioluminescent nanoparticle probes injected into biological tissue is performed by irradiated the tissue with ionizing radiation to induce radioluminescence at optical wavelengths, preferably at predetermined near infrared wavelengths. The optical light is detected and processed to determine a spatial distribution of the probes. The radioluminescent nanoparticles may be inorganic or organic phosphors, scintillators, or quantum dots. Imaging systems realizing this technique include tomographic systems using an x-ray beam to sequentially irradiate selected regions, systems with a radioactive source producing the ionizing radiation from outside the tissue, such as with a beam, or inside the tissue, such as with an endoscope or injected radiopharmaceutical.

Abstract: Line segments are classified according to orientation to improve list mode reconstruction of tomography data using graphics processing units (GPUs). The new approach addresses challenges which include compute thread divergence and random memory access by exploiting GPU capabilities such as shared memory and atomic operations. The benefits of the GPU implementation are compared with a reference CPU-based code. When applied to positron emission tomography (PET) image reconstruction, the GPU implementation is 43× faster, and images are virtually identical. In particular, the deviation between the GPU and the CPU implementation is less than 0.08% (RMS) after five iterations of the reconstruction algorithm, which is of negligible consequence in typical clinical applications.

Abstract: Methods and systems for determining a sequence of energy interactions in a detector. A plurality of discrete energy interactions is received in a plurality of detector voxels. A plurality of possible sequences of interaction is formed based on the received plurality of discrete energy interactions. For each of the plurality of possible sequences of interaction, an a posteriori probability is computed, where the a posteriori probability is based on a likelihood that the possible sequence of interaction is consistent with the received plurality of discrete energy interactions. Additionally or alternatively, the a posteriori probability may be based on an a priori probability. One of the formed plurality of possible sequences of interaction is selected based on the computed a posteriori probability.

Abstract: The present invention provides a method of reconstructing a tomographic image. In a first step, a tomographic image is forward-projected along a list of geometrical lines in a GPU. This list of geometrical lines may be list-mode event data acquired from a tomographic scanner. Alternatively, the list may be a list of weighted lines derived from a sinogram, a histogram, or a timogram acquired from a tomographic scanner. Next, the list of geometrical lines is back-projected into a 3-dimensional volume using the GPU. The results of the forward- and back-projection are then used to reconstruct the tomographic image, which is then provided as an output, e.g. to make the image available for further processing. Examples of output include storage on a storage medium and display on a display device.