Abstract: An improved system and method for tuning individual sensors (e.g., photomultiplier tubes) of a multi-sensor imaging system such as e.g., a gamma camera having an array of photo-multiplier tubes is provided that produces a uniform response over the entire system. Individual sensors of a multi-sensor imaging system are tuned based explicitly or implicitly on gain characteristics of individual sensors of the multi-sensor imaging system so as to produce a uniform response over the system.

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: 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: A phoswich device for determining depth of interaction (DOI) includes a wavelength shifting layer between first and second scintillators of different scintillation materials and having different decay time characteristics. The wavelength shifting layer allows a true phoswich device to be constructed where the emission wavelength of one scintillator is in the peak excitation band of the other scintillator, by shifting the scintillation light outside of this excitation band to prevent scintillation light of one scintillator from exciting a response in the other scintillator, thus enabling unique identification of the location of a gamma photon scintillation event. The phoswich device is particularly applicable to positron emission tomography (PET) applications.

Abstract: The present invention provides a method of real-time crystal peak tracking for avalanche-photodiode (APD) detectors on positron emission tomography (PET) scanners that satisfies the need to compensate for the significant gain drifting due to thermal variations in APD detectors on PET scanners.

Abstract: A single crystal pull apparatus has a multilayer crucible wherein the crucible has an outer crucible, an insertable layer intimately fitted thereon, and a wire frame positioned between the insertable layer and an inner crucible. The insertable layer, wire frame and inner crucible are preferably composed of platinum. Furthermore the insertable layers have thin walls and the frame has a small diameter such that they can be easily reshaped after any deformation occurring as a result of the single crystal growth process.

Abstract: Determining a scintillation event location bevent along an axis B of an array of photomultiplier tubes, each photomultiplier tube having a location bPMT and an output ZPMT. Determining a preliminary event location bprelim along the B axis as a centroid of the photomultiplier tube outputs. Determining a position-weighted characteristic (ZPMT·(bPMT?bprelim)2) of each of the photomultiplier tubes. Determining event location bevent along the B axis as a centroid of the outputs of those photomultiplier tubes characterized by a position-weighted characteristic less than or equal to a predetermined cutoff.

Abstract: Time-of-flight (TOF) clinical data collected during a PET scan are very sparse and have significant size. These data undergo TOF axial rebinning and azimuthal mashing if histogrammed data-based reconstruction algorithms are used. In a clinical environment, TOF compression is typically performed by the hardware rebinner. Normalization data, acquired on a regular basis and used for estimation of some norm components, are compressed by the hardware rebinner in a similar manner. This disclosure presents simple update iterative algorithms for crystal efficiencies norm component estimation from TOF compressed normalization data. Previously known methods are not directly applicable since the compression procedure significantly complicates normalization data model equations. The iterative algorithms presented herein have advantages of being easily adapted to any acquisition geometry, and of allowing estimation of parameters at crystal level when a number of crystals is relatively small.

Abstract: An iterative reconstruction method to reconstruct an object includes determining, in a series of iteration steps, updated objects, wherein each iteration step includes determining a data model from an input object, and determining a stop-criterion of the data model on the basis of a chi-square-gamma statistic. The method further includes determining that the stop-criterion of the data model has transitioned from being outside the limitation of a preset threshold value to being inside the limitation, ending the iterations, and selecting one of the updated objects to be the reconstructed object.

Abstract: A computer-implemented method of assessing the quality of a functional image for an object includes causing a computer to execute instructions for providing a signal distribution of values N generating a transformed distribution by calculating, for each value N, a transformed value X=?{square root over (N+¼)}, reconstructing the functional image from the signal distribution, deriving an expected distribution of expected values ? from the functional image, generating a residual distribution by calculating, for each value N, a residual values ?X=X??{square root over (?)}, and outputting the residual distribution.

Abstract: A method, process and apparatus for compensating for changes to the gain of photo detectors in a nuclear imaging apparatus is disclosed. Specifically, embodiments detect positron annihilation event pulses using photo detectors. Changes to the gain of the photo detectors are compensated for by determining the relationship of a detected event pulse peak with a target event pulse peak. Based on the difference between these two peaks, a corrected gain is determined in a closed-loop control system. The corrected gain can be used to compensate for temperature changes that can affect the gain of the photo detectors.

Abstract: A representative positron emission tomography (PET) calibration system includes a PET scanner having a ring detector, a phantom that is placed at approximately the center of the ring detector, and a time alignment calibration manager that is coupled to the PET scanner. The time alignment calibration manager detects coincidence events from the phantom, calculates position of time of flight events from the ring detector based on the detected coincidence events, and calculates time offsets for the ring detector using a mean value calculation based on the calculated position of the time of flight events.

Abstract: Tomographically reconstructing a 3D image object corresponding to a data set includes reconstructing a first reconstructed object from the data set, receiving a smoothing map, smoothing the first reconstructed object based on the smoothing map thereby creating a first smoothed object, and outputting the first smoothed object as the 3D image object. Smoothing a first object thereby creating a smoothed object having a smoothed value associated to each object point in object space includes receiving the first object, determining, in a series of steps, single-kernel-smoothed objects, wherein each iteration step is associated with a kernel function and includes, determining a start object based on the first object, and smoothing the start object using the kernel function of the iteration step, thereby creating the single-kernel-smoothed object having single-kernel-smoothed values associated to each object point, and constructing the smoothed object from the single-kernel-smoothed values.

Abstract: Systems and methods are described for co-registering, displaying and quantifying images from numerous different medical modalities, such as CT, MRI and SPECT. In this novel approach co-registration and image fusion is based on multiple user-defined Regions-of-Interest (ROI), which may be subsets of entire image volumes, from multiple modalities, where the each ROI may depict data from different image modalities. The user-selected ROI of a first image modality may be superposed over or blended with the corresponding ROI of a second image modality, and the entire second image may be displayed with either the superposed or blended ROI.

Abstract: In an aspect, 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 smoothing operation, and following a last iteration, outputting one of the updated objects as the 3D image object.

Abstract: A method of making LSO scintillators with high light yield and short decay times is disclosed. In one arrangement, the method includes codoping LSO with cerium and another dopant from the IIA or IIB group of the periodic table of elements. The doping levels are chosen to tune the decay time of scintillation pulse within a broader range (between about ˜30 ns up to about ˜50 ns) than reported in the literature, with improved light yield and uniformity. In another arrangement, relative concentrations of dopants are chosen to achieve the desired light yield and decay time while ensuring crystal growth stability.

Abstract: A method and apparatus for correcting misalignment between fields of view of a CT device and a NM device of a modular multimodality medical imaging system, by providing a Field Of View Calibration Matrix (FOV-CM) containing rotational and translational transformations between coordinate systems of the CT and NM systems.

Abstract: PET system including array, data processing, and data acquisition. Data acquisition includes one-to-N channel write striping, N-to-one channel read unstriping, N data storage elements, and control logic. Control logic allocates (statically or dynamically) write/read access to data storage elements. Dynamic allocation can be conditional, e.g., that data storage elements be available to receive all input data from array. Embodiments include an input buffer where the condition is determined dynamically based on capacity of the input buffer to temporarily preserve all input data supplied during periods data storage element unavailability. Communication between array and data acquisition can be Fibre Channel simplex implementing only FC-0, FC-1. Data storage elements have data handling bandwidth equal to or greater than (data output rate /N) plus (data input rate/N). Control logic, write striping, read unstriping can be implemented in FPGA. Data storage elements can form a Redundant Array of Independent Disks, e.

Abstract: A method for improving clinical data quality in Positron Emission Tomography (PET). The method provides for the processing of PET data to accurately and efficiently determine a data signal-to-noise (SNR) corresponding to each individual clinical patient scan, as a function of a singles rate in a PET scanner. The method relates an injected dose to the singles rate to determine SNR(Dinj), and provides an accurate estimate of quantity proportional to SNR, similar in function to SNR(Dinj). Knowledge of SNR(Dinj) permits determination of peak SNR, optimal dose, SNR deficit, dose deficit, and differential dose benefit. The patient dose is fractionated, with a small calibration dose given initially. After a short uptake, the patient is pre-scanned to determine T, S, and R. An optimal dose is then determined and the remainder is injected.

Abstract: Methods of nuclear imaging can include, in a pre-scan, detecting radiation emitted from a patient in a first plurality of viewing angles including at least a first viewing angle and a second viewing angle, generating nuclear data from the detected radiation, reconstructing a first nuclear event distribution from the nuclear data, selecting a region of interest, determining a first signal-to-noise ratio of the first nuclear event distribution within the region of interest, selecting a second plurality of viewing angles not including the first viewing angle, reconstructing a second nuclear event distribution from the nuclear data associated with the second plurality of viewing angles, determining a second signal-to-noise ratio of the second nuclear event distribution within the region of interest, determining that the second signal-to-noise ratio is greater than or equal to the first signal-to-noise ratio, and nuclear imaging the patient by detecting nuclear data based on a nuclear imaging process that is based