Abstract: In positron emission tomography (PET), a detector's response to scattered radiation may be different from its response to unscattered (true coincidence) photons. This difference should be accounted for during normalization and scatter correction. The disclosure shows that only a knowledge of the ratio of the scatter to trues efficiencies is necessary, however. A system and method are disclosed for measuring the scatter/trues detection efficiency ratio, as well as for applying this compensation during the scatter correction of PET emission data. PET detector efficiencies are measured in two steps, the first using a plane radiation source, and the second using a plane radiation source in combination with a scattering medium. A ratio of the scatter and trues detection efficiency is obtained from this data for each detector/crystal, and is applied as a correction factor to PET data obtained during medical imaging processes.

Abstract: A mounting assembly for attaching the drive system and stand to a ring in a medicine gantry is disclosed. The mounting assembly includes at least one mounting bar (e.g., two mounting bars), at least one mounting plate and at least one adjuster (e.g., a screw). The mounting bar is securable to a portion of the ring. The mounting bar includes a base and at least one transverse face. At least a portion of the base is substantially parallel to a surface of a portion of the ring and at least a portion of the transverse face is substantially perpendicular to the surface of the portion of the ring. The mounting plate is secured to the drive system and is securable to the transverse face of the mounting bar. Movement of the adjuster moves the drive assembly relative to the mounting bar when the mounting plate is adjacent the transverse face of the mounting bar.

Abstract: In an aspect, reconstructing an image object associated with an input data set, includes for each step, in a series of iteration steps, determining an updated object from an input object based on a data model of the input object, a weighting-factor data set, and a gradient object, wherein the weighting-factor data set includes modified entries of the input data set. Reconstructing the image object further includes following a last iteration, outputting one of the updated objects as the image object.

Abstract: A method for iterative reconstruction of tomographic images of an object of interest includes obtaining data corresponding to a field of view of a detector, processing the data to prepare a reconstruction support region corresponding to a region within the field of view encompassing the object, and reconstructing a tomographic image using the reconstruction support region. Preferably, the data corresponding to the field of view includes at least one of a projection image of the object, an orbit location of a detector relative to a center of rotation of the detector, or an attenuation coefficient map of the object, which data can be used to describe a reconstruction support region corresponding to the object.

Abstract: According to some embodiments, a patient support system for a nuclear medical imaging system is provided that includes: a patient support; a collimator storage unit located under the patient support; a first support means for supporting substantially all of the weight of the collimator storage unit; and a second support means for supporting the patient support at least at a position distal from a gantry of the nuclear medical imaging system. In some embodiments, the first support means includes means for supporting the patient support at a position proximate a gantry of the nuclear medical imaging system and the second support means includes two vertical support structures. In addition, the system preferably includes at least one laterally extendable frame member mounted between the two vertical support structures.

Abstract: A system for simulating a Positron Emission Tomography (PET) gantry has a computer system having a bus system for receiving expansion cards, a mass data storage support system, the mass storage system being operable to store coincidence-event and tag packet data, and a data transfer simulation card for said bus system, wherein the data transfer simulation card is operable to simulate transfer timing of the stored coincidence-event and tag packet data.

Abstract: A system and method for rendering images, and performing operations such as windowing and leveling, when the parameters of a client appliance are known and rendering images when the parameters of a client appliance are unknown. The invention also considers the rendering from the client appliance perspective and the server appliance perspective.

Abstract: Tomographically reconstructing a 3D image object corresponding to a data set includes for each step in a series of iteration steps, determining an updated object by performing a combined operation, which includes performing an update operation for updating an input object and performing a pixon smoothing operation, and following a last iteration, outputting one of the updated objects as the 3D image object.

Abstract: An apparatus and method for expanding the FOV of a truncated computed tomography (CT) scan. An iterative calculation is performed on the original CT image to produce an estimate of the image. The calculated estimate of the reconstructed image includes the original image center and a estimate of the truncated portion outside the image center. The calculation uses an image mask with the image center as one boundary.

Abstract: A PET event position calculation method using a combination angular and radial event map wherein identification of the radial distance of the event from the centroid of the scintillation crystal with which the event is associated as well as angular information is performed. The radial distance can be converted to a statistical confidence interval, which information can be used in downstream processing. More sophisticated reconstruction algorithms can use the confidence interval information selectively, to generate higher fidelity images with higher confidence information, and to improve statistics in dynamic imaging with lower confidence information.

Abstract: A phoswich device for determining depth of interaction (DOI) includes a first scintillator having a first scintillation decay time characteristic, a second scintillator having a second scintillation decay time characteristic substantially equal to the first scintillation decay time, a photodetector coupled to the second scintillator, and a wavelength shifting layer coupled between the first scintillator and the second scintillator, wherein the wavelength shifting layer modifies the first scintillation decay time characteristic of the first scintillator to enable the photodetector to differentiate between the first decay time characteristic and the second decay time characteristic. The phoswich device is particularly applicable to positron emission tomography (PET) applications.

Abstract: A method of tuning an imaging system can include the steps of receiving photons at photo-multiplier units that are part of an array, determining an energy level for each of the photo-multiplier units based on events over a specific photo-multiplier unit and determining a sum energy level for the array of photo-multiplier units based on the events over the specific photo-multiplier unit. The method can also include the step of comparing the energy level for each of the photo-multiplier units with the sum energy level for the array of photo-multiplier units to assist in determining a contribution matrix for the array of photo-multiplier units. The energy level determination steps and the comparison step can be repeated for each photo-multiplier unit in the array to determine the contribution matrix.

Abstract: A method and system for mitigations brake failure in a medical device. The method and system includes a motion system for at least one movable load. Each movable load has a drive, a controller for the drive, and a brake. The controller is adapted to monitor positional parameters of the drive or electrical parameters of the brake or a combination of both. The method involves the step of monitoring the parameters and evaluating the parameters to detect a brake failure of the brake.

Abstract: A partitioned pipeline read-out circuit architecture eliminates real-time constraints from off-chip read-out control electronics in a solid-state radiation detector system, so that an efficient decoupled architecture is possible. The front-end electronics includes a multi-channel ASIC with independently triggered charge sensitive pre-amplifiers, shaper circuits, and switched sample-and-hold capacitor circuits for each photodiode or pixel of the detector module. With this structure, individual photodiodes of the photodetector array can detect and store scintillation events independently and randomly. The ASIC is interfaced to an external successive approximation A/D converter for conversion and subsequent input to a data processing apparatus.

Abstract: A vented filter is placed at the HPLC (High Performance Liquid Chromatography) loop entry port of an HPLC injector valve. The vented filter prevents the push gas used to deliver the crude radiolabeled product from over-pushing the liquid to waste. Push gas is vented off when the entire crude liquid product has passed through the vented filter and been loaded onto the HPLC loop.

Abstract: A computer-implemented method includes causing a computer system to execute instructions for providing a first data set and a second data set, each derived from a common object, providing a first tomographic image object associated with the first data set providing a second tomographic image object associated with the second data set, generating a multimodal pixon map for pixon smoothing on the basis of the first data set, the first tomographic image object, the second data set, and the second tomographic image object, and outputting the multimodal pixon map.

Abstract: Determining a pixon map for pixon smoothing of an object based on a data set includes receiving the data set and an input object associated to the data set. Determining a pixon map further includes determining, in a series of steps, statistical objects for a set of pixon kernel functions, wherein each step includes selecting a pixon kernel function from the set of pixon kernel functions, smoothing the input object on the basis of the selected pixon kernel function, thereby creating a smoothed object, and determining the statistical object for the selected pixon kernel function on the basis of the smoothed object, the data set, and a Mighell-like statistical weight. Determining a pixon map further includes determining contributions of the pixon kernel functions to the pixon map based on the statistical objects and assigning values to the pixon map corresponding to the contributions of the pixon kernel functions.

Abstract: A method and system for spatially localized, noise-adaptive smoothing of filtered back-projection (FBP) nuclear images includes smoothing a FBP image on a pixel-by-pixel basis using a shift-invariant kernel such as a Gaussian kernel. The width of the kernel may be varied on a pixel basis, such that the smoothed image contains a constant SNR over the entire image.

Abstract: A method and system of increasing the speed of a ray-casting algorithm for producing direct volume rendering images in the melt-through interaction mode. Since the viewing direction is not changed during a melt-through interaction, it is possible to reuse the samples calculated along each ray from one frame to another. The samples along each ray are partitioned into different groups, and the samples within each partition can be composited to generate an RGBA-tuple (Red Green Blue and Alpha, which is an opacity factor) for the partition. The associative property of the composition operation allows computation of the final RGBA value for each ray by compositing the RGBA-values of the partitions, instead of compositing the RGBA-values of each sample along the ray.

Abstract: An apparatus for containing and cooling enriched water for the production of activated fluorine (18F). A target assembly includes internal cooling channels in which developed flow of a coolant removes the heat from the target liquid in the target chamber. In one embodiment, the target assembly is fabricated of tantalum.