Abstract: Using complementary reconstruction, images from short time frames may be generated for positron emission tomography. Detected events are gathered over a long period, such as three minutes. The detected events from a short period, such as one or two seconds, are removed. Reconstruction is performed on the detected events from the long period and another reconstruction is performed on the detected events from the long period without the detected events from the short period. The second reconstruction is subtracted from the first, providing data representing the short period. The data may result in better image quality than merely reconstructing an individual frame for the short period.

Abstract: A data processing process and embodiment for optimizing the signal path for multi-modality imaging is described. The embodiment and process optimizes the signal to noise ratio in a positron emission tomography (PET) signal path utilizing scintillation crystals, avalanche photo diodes, and charge sensitive preamplifiers in a dual modality MRI/PET scanner. The dual use of both and analog pole zero circuit and a digital filter enables higher signal levels or a fixed ADC input range and thus a higher possible signal to noise ratio in the presence of significant pileup caused by high positron activity. The higher signal to noise ratio is needed in the PET signal architecture, because of the presence of non-modal time varying electromagnetic fields from the MR, which are a significant source of noise for the wideband PET signal modality.

Abstract: Methods, and systems therefrom, for generating images from time of flight (TOF) data associated with a scan of at least one object using a positron emission tomography system are provided. The method includes providing initial values for an activity image to yield a current activity image. The method also includes estimating initial values for an attenuation map (?-map) image based on the TOF data to yield a current ?-map image. The method further includes repeating, until at least one termination condition is met, the steps of updating the current activity image based on at least the current ?-map and a first update algorithm and updating the current ?-map image based on at least on the updated activity image and a second update algorithm. The method also includes outputting an image of the at least one object based on the current ?-map and the current activity image.

Abstract: An event data transmission scheme is provided for reducing positron emission tomography event losses. The event data transmission scheme employs a more effective use of available data bandwidth. Each of a plurality of detector data slots is connected directly to a data aggregation control interface, and the control interface is connected to a coincidence processor.

Abstract: Methods and computer-readable mediums are provided. In one embodiment, the method acquires patient data. The peak value in the patient data is determined. The patient data is divided into two data segments (i.e., one data segment representing the data before the peak value occurs and a second data segment representing the patient data after the peak occurs). The slopes of the first and second data segments are calculated. Thereafter the slopes are used to determine an appropriate adaptive framing protocol. A number of frames and duration of each frame in the adaptive framing protocol can be calculated or the adaptive framing protocol can be selected from a plurality of framing protocols. Embodiments of the invention also include computer-readable mediums that contain features similar to the features in the above described method.

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 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: 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: A system identifies when received packets are lost at a node in a multi-node processing chain. The system processing chain may include a gantry interface module for receiving coincident event data from a PET (Positron Emission Tomography) detector array, a DMA (direct memory access) rebinner card, and a transmission line coupled between the gantry interface module and the DMA card. FPGA and FIFO elements in each processing portion receive packets that may be lost if there is insufficient FIFO capacity. Lost packets are marked, discarded, and counted. At specified intervals, set in accordance with a threshold number of packets received a lost tally data packet is generated that includes count information for lost packets. The lost tally data packet is forwarded downstream when sufficient storage capacity exists.

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: A method for processing an image which has the steps of a) receiving acquired data necessary to obtain an image and estimating a preliminary image; b) selecting at least one image element within the image; c) performing an iterative algorithm for processing the image at least on the at least one image element; d) computing a difference between the processed at least one image element and the at least one image element; and e) repeating the steps c) and d) until the difference is below a predefined threshold.

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: A method for correcting PET emission data for prompt gamma emission background components present in non-pure positron-emitting isotopes uses a two component fit of modeled scatter and modeled prompt gamma emission in the area of scatter tails in a normalized emission sinogram. The method allows a PET scan using non-standard PET isotopes to be quantitative and thus more clinically useful.

Abstract: The present invention provides a method for estimating crystal efficiency in a PET detector that takes axial compression into account. It does so via an iterative methodology in which a ?-map is first generated and then is used to obtain a solution for the equation L ? ( ? i ) = ? n ? N ? ? y n ? log ? ? i , j ? span ? ? g ij ? ? i ? ? j ? x ij - ? i , j ? span ? ? g ij ? ? i ? ? j ? x ij , wherein gij is a geometric factor for LOR(i,j), ?i and ?j are the efficiencies for crystal i and crystal j, and xij is the line integral of the source distribution along LOR(i,j). Once efficiencies are determined, they are used to calibrate the PET detector.

Abstract: A method and system for reconstructing PET image data from a cylindrical PET scanner by incorporation of axial system response. The method includes the steps of: assuming the decomposition of axial components into individual line-of-response (LOR) contributions, approximating each LOR spreading in image space as depth-independent, implementing each LOR response, combining the LORs to produce large span projection data, implementing the back projector as a transposed matrix, and assembling the LOR projections and spans for each azimuthal angle.

Abstract: A method for determining quality of sinograms produced by a medical imaging device. The method may include placing a uniform phantom object in the field of view of the medical imaging device; acquiring one or more phantom sinograms of the uniform phantom object; establish a set of parameters for the acquired one or more phantom sinograms; and determine, based on pre-set ranges of the parameters, the quality of sinograms produced by the medical imaging device. The parameters may be one or more parameters of a group of parameters consisting of block uniformity, block efficiency, randoms rate, scanner efficiency, and scatter ratio.

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 single-to-noise ratio (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 a quantity proportional to SNR, similar in function to the 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 does is then determined and the remainder injected.

Abstract: Axial rebinning methods are provided for 3D time-of-flight (TOF) positron emission tomography (PET), based on 2D data rebinning. Rebinning is performed separately for each axial plane parallel to the axis of the PET scanner. An analytical approach is provided that is based on a consistency condition for TOF-PET data with a gaussian profile. A fully discrete approach is also provided, wherein each 2D TOF-PET data is calculated as a linear combination of 3D TOF-PET data having the same sinogram coordinates s and ?.

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 single-to-noise ratio (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 a quantity proportional to SNR, similar in function to the 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 does is then determined and the remainder injected.

Abstract: A method of TOF-PET image reconstruction using time-truncated TOF-PET projection data. The time-truncated TOF-PET data is obtained by narrowing the scanner time window to a smaller “time window field of view,” which reduces the field of view of a TOF-PET scanner. This results in a lower list mode stream transfer rate, which can be useful in high count rate data acquisitions, in particular 82Rb cardiac studies.