Abstract: A method and apparatus are provided for reducing motion related imaging artifacts. The method includes determining an internal motion for of two regions of the object, each region having a different level of motion, scanning the first region using a first scan protocol based on the motion, scanning a second region using a second different scan protocol based on the motion, and generating an image of the object based on the first and second regions.

Abstract: Embodiments relate to a slit collimator assembly including a first set of panels spaced at least partially around a longitudinal axis of the collimator assembly and extending generally parallel to the longitudinal axis. The slit collimator assembly further includes a second set of panels spaced at least partially around longitudinal axis of the collimator assembly and extending generally parallel to the longitudinal axis. The first set of panels and the second set of panels are arranged to define one or more slit apertures. The slit collimator assembly is configured so that movement of at least one of the first set of panels or the second set of panels adjusts an aperture size of at least one of the one or more slit apertures. The slit collimator assembly is configured so that gamma rays can pass through the one or more slit apertures, but the remainder of the collimator assembly is substantially gamma ray absorbent. Embodiments also relate to imaging systems and methods of changing collimator performance.

Abstract: The method calculates a scatter estimate for scatter correction of detection data from a subject in a positron emission tomographic scanner. The detection data represent the scattered events and unscattered events of annihilation photons emitted in the subject. The method uses the following steps: determine an estimate of the unscattered events; determine a simulation of the scattered events; determine a value of a scaling factor by fitting the sum of the estimate of the unscattered events and a product of the scaling factor and the simulation of the scattered events to the detection data; and determine the scatter estimate as the product of the scaling factor having said value and the simulation of the scattered events.

Abstract: A method and system for fluorescence imaging of a target in a subject comprising a scattering medium is provided. The method comprises illuminating one or more points on a surface of the scattering medium using an illumination source, wherein the plurality of points define an illumination region, collecting emitted light from an illumination region and an area away from the illumination region, and generating an image of the scattering medium using the emitted light.

Abstract: Embodiments relate to an imaging system that includes a collimator assembly having one or more pinhole apertures therein. The imaging system is configured so that one or more of the pinhole apertures has an adjustable focal length. The imaging system further includes a detector assembly configured to generate one or more signals in response to gamma rays that pass through the one or more pinhole apertures. Embodiments also relate to methods of changing collimator performance and methods of imaging a volume.

Abstract: An imaging system includes a platform having mounted thereon a coded-aperture imaging device and positioned to receive radiation over a baseline. The imaging system includes a computer configured to acquire a plurality of far-field datasets over the baseline, the plurality of far-field datasets comprising data received via the coded-aperture imaging device. The computer is also configured to form a preliminary image based on the acquired plurality of far-field datasets, and apply an expectation maximization (EM) algorithm to the preliminary image; wherein the EM algorithm includes an ordered subset algorithm.

Abstract: An imaging system includes a platform having mounted thereon a coded-aperture imaging device and positioned to receive radiation over a baseline. The imaging system includes a computer configured to acquire a plurality of far-field datasets over the baseline, the plurality of far-field datasets comprising data received via the coded-aperture imaging device. The computer is also configured to form a preliminary image based on the acquired plurality of far-field datasets, and apply an expectation maximization (EM) algorithm to the preliminary image; wherein the EM algorithm includes an ordered subset algorithm.

Abstract: Embodiments relate to collimator assemblies having one or more apertures therein. At least one of the one or more apertures has an aperture size that is configured for adjustment during an examination. The collimator assembly is configured so that gamma rays can pass through the one or more apertures, but the remainder of the collimator assembly is substantially gamma ray absorbent. Embodiments also related to imaging systems and methods of imaging.

Abstract: Embodiments relate to an imaging system that includes a collimator assembly having one or more pinhole apertures therein. The imaging system is configured so that one or more of the pinhole apertures has an adjustable focal length. The imaging system further includes a detector assembly configured to generate one or more signals in response to gamma rays that pass through the one or more pinhole apertures. Embodiments also relate to methods of changing collimator performance and methods of imaging a volume.

Abstract: Collimator assemblies that include an outer slit collimator having one or more slits therein, and an inner slit collimator having one or more slits therein are provided. Imaging systems that include a collimator assembly and a detector array are also provided. The collimator assembly includes an outer slit collimator having one or more slits therein. The collimator assembly further includes an inner slit collimator having one or more slits therein. The imaging system also includes a detector array configured to detect gamma rays emanating from a field of view that pass through one or more apertures defined by the collimator assembly. The detector array is further configured to generate one or more signals in response to the detected gamma rays. Methods of imaging a field of view using the imaging system are also provided.

Abstract: Embodiments of the present technique relate to a modular multi-hole collimator assembly configured to have an adjustable length. Each of the two or more multi-hole collimator units has a plurality of holes therethrough. Exemplary embodiments also relate to a modular multi-hole collimator assembly that includes a base multi-hole collimator unit and one or more multi-hole collimator extension units. Each of the base multi-hole collimator unit and the one or more multi-hole collimator extension units has a plurality of holes therethrough. At least one of the plurality of holes through the base multi-hole collimator unit and at least one of the holes through the one or more multi-hole collimator extension units are axially aligned.

Abstract: A method and system for fluorescence imaging of a target in a subject comprising a scattering medium is provided. The method comprises illuminating one or more points on a surface of the scattering medium using an illumination source, wherein the plurality of points define an illumination region, collecting emitted light from an illumination region and an area away from the illumination region, and generating an image of the scattering medium using the emitted light.

Abstract: Embodiments relate to pinhole collimator assemblies having one or more adjustable size pinhole apertures therein. The pinhole collimator assembly is configured so that gamma rays can pass through the collimator assembly, but the remainder of the collimator assembly is substantially gamma ray absorbent. Embodiments also relate to imaging systems and methods of adjusting pinhole collimator performance.

Abstract: Embodiments relate to a slit collimator assembly including a first set of panels spaced at least partially around a longitudinal axis of the collimator assembly and extending generally parallel to the longitudinal axis. The slit collimator assembly further includes a second set of panels spaced at least partially around longitudinal axis of the collimator assembly and extending generally parallel to the longitudinal axis. The first set of panels and the second set of panels are arranged to define one or more slit apertures. The slit collimator assembly is configured so that movement of at least one of the first set of panels or the second set of panels adjusts an aperture size of at least one of the one or more slit apertures. The slit collimator assembly is configured so that gamma rays can pass through the one or more slit apertures, but the remainder of the collimator assembly is substantially gamma ray absorbent. Embodiments also relate to imaging systems and methods of changing collimator performance.

Abstract: Embodiments relate to collimator assemblies having one or more apertures therein. At least one of the one or more apertures has an aperture size that is configured for adjustment during an examination. The collimator assembly is configured so that gamma rays can pass through the one or more apertures, but the remainder of the collimator assembly is substantially gamma ray absorbent. Embodiments also related to imaging systems and methods of imaging.

Abstract: Embodiments relate to pinhole collimator assemblies having one or more adjustable size pinhole apertures therein. The pinhole collimator assembly is configured so that gamma rays can pass through the collimator assembly, but the remainder of the collimator assembly is substantially gamma ray absorbent. Embodiments also relate to imaging systems and methods of adjusting pinhole collimator performance.

Abstract: Collimator assemblies that include an outer slit collimator having one or more slits therein, and an inner slit collimator having one or more slits therein are provided. Imaging systems that include a collimator assembly and a detector array are also provided. The collimator assembly includes an outer slit collimator having one or more slits therein. The collimator assembly further includes an inner slit collimator having one or more slits therein. The imaging system also includes a detector array configured to detect gamma rays emanating from a field of view that pass through one or more apertures defined by the collimator assembly. The detector array is further configured to generate one or more signals in response to the detected gamma rays. Methods of imaging a field of view using the imaging system are also provided.

Abstract: Embodiments include an imaging system that includes a collimator support base and a detector assembly. The collimator support base is configured to interchangeably accept a slit aperture collimator and a pinhole aperture collimator. The slit aperture collimator has either a corresponding septa assembly or a corresponding crossed-slit collimator. The detector assembly is configured to detect collimated gamma rays emanating from a subject in a field of view of the imaging system and generate one or more signals in response to the detected gamma rays. Methods of adjusting performance of imaging systems are also provided.

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: Collimator assemblies that include an inner combined collimator and an outer collimator are provided. The inner combined collimator includes a first portion having one or more slit apertures therein, and a second portion having one or more pinhole apertures therein. The outer collimator includes one or more septa spaced on a side of the first portion of the inner combined collimator. The slit apertures of the inner combined collimator and the septa of the outer collimator are arranged to define a plurality of apertures through the collimator assembly. Imaging systems that include the collimator assemblies and a detector assembly are also provided. The detector assembly may be configured to detect gamma rays emanating from a field of view that pass through apertures defined by the collimator assembly and to generate one or more signals in response to the detected gamma rays. Methods of imaging a field view using the collimating assembly are also provided.