Cti Pet Systems, Inc.

Siemens Medical Solutions Usa, Inc.

Cti, Inc.

William F Jones

Michael E Casey

Johnny H Reed

John E Breeding

Ronald Nutt

Charles C Watson

J Clifton Moyers

Jimmy Everman

Wing K Luk

Andrew Philip Moor

Bernard Bendriem

David W Townsend

Bryan Castleberry

Larry G Byars

A patient bed drive mechanism, under control of a processor, is capable of continuously moving a patient bed through the a TOF-PET detector array having a stationary field of view (FOV) for a distance in excess of the physical extent of an axis of the array FOV. A direct memory access (DMA) rebinner card is coupled to the detector array to receive therefrom a stream of TOF-PET coincidence event data during the extent of movement of the bed. Image projection data are generated in real time from the acquired stream of TOF-PET coincidence event data via the DMA card.

On-line TOF-PET mashed rebinning for continuous bed motion acquisitions

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.

System for simulating PET gantry

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.g., RAID 0.

Positron emission tomography event stream buffering

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.

Defining lost event talley tag packets when PET count rates exceed available acquisition bandwidth

A device for improved on-line histogramming of data acquired in a Positron Emission Tomography (PET) scan. The device is a Smart DRAM (SD) PCI card, of which more than one can be used in combination within a PC-based architecture for on-line histogramming. The SD PCI card is applied as either of a Gating Buffer, a histogramming card, and a normalization buffer. The Gating Buffer card alternately stores an arriving PET data packet stream into two dedicated DRAM banks. The two DRAM banks store and retransmit the packet stream in the order of arrival for an entire physiological cycle. The histogramming SD RMW PCI cards provide a very high rate of histogramming. The extendible daisy-chain of SD RMW PCI cards supports large memory banks across potentially hundreds of SD RMW PCI cards. Under a single PC, a multiple PCI Expansion chassis is employed such that a large number of PCI cards are supported.

Device for on-line data acquisition in three-dimensional positron emission tomography

A system for generating time-of-flight (TOF) positron emission tomography (PET) projection data includes a direct memory access rebinner constructed as a digital FPGA pipeline for rebinning TOF coincidence data in accordance with a number of projection space mapping algorithms, such as single-slice rebinning (SSRB) and reduced multiple-slice rebinning (MSRB), together with less precise transaxial and/or axial sampling.

On-line time-of-flight mashing: DMA rebinning applied to a long-axis PET-TOF system for reduced transaxial angular sampling with 3-D nearest-neighbor projection-space rebinning in clinical PET/CT

A projection data rebinning device for nearest-neighbor rebinning in Positron Emission Tomography (PET) using on-line 3D axial LOR-to-bin mapping. The PETLINK&#x2122; DMA Rebinner (PDR) of the present invention includes a PCI card for on-line translation of detector-pair event packets into bin-address packets. The PDR delivers accurate axial and transaxial LOR nearest-neighbor rebinning and enables the more oblique LOR to be mapped into the proper sinogram bins. The PDR is used in association with hardware architecture in electrical communication with a medical imaging device. The data acquisition architecture includes a processor, random access memory (RAM), an operating system, and a data storage device. The PDR includes a plurality of FPGAs and flash chips. The FPGAs are in communication with each other via a high-bandwidth connection. The flash memory chips are used for look-up tables. The PDR performs on-line translation of detector-pair event packets into bin-address packets.

Nearest-neighbor rebinning in clinical PET using on-line three dimensional LOR-to-bin mapping

A device and method for on-line correction of patient motion in three-dimensional positron emission tomography. The devices encompass an on-line hardware pipelining architecture to support 3D translation, normalization, and weighted histogramming as required. Five stages of processing for the PET event stream are utilized in the present invention. Each stage feeds the next with progressively modified event packets proceeding at a processing speed of at least 10M packets/sec. Stagecalculates an event correction factor (ECF) for each incoming detector-pair event packet. This ECF is incorporated into the event packet for use later in StageStageconverts the detector-index-pair content of each packet into (x,y,z) pair content. Specifically, the representation of each detector element is converted from a discrete crystal index into a 3-D coordinate index. Stagetransforms the (x,y,z) pair into an (x',y&#x2032;,z&#x2032;) pair. Stageconverts the (x&#x2032;,y&#x2032;,z&#x2032;) pair into a bin address. Output from Stageis a normalized projection data set available at the end of each acquisition frame. Stageperforms on-line weighted histogramming.

On-line correction of patient motion in three-dimensional positron emission tomography

A device and method for on-line correction of patient motion in three-dimensional positron emission tomography. The devices encompass an on-line hardware pipelining architecture to support 3D translation, normalization, and weighted histogramming as required. For the 3D translation circuit, a first digital pipeline latch is provided for receiving data as it is collected by the PET scanner. A bank of multiplier circuits receives the PET scan data. Each multiplier circuit receives and multiplies a portion of the entire scan data simultaneous with each other multiplier circuit. The product of each multiplier circuit is output to a second digital pipeline latch. The data is then passed to a bank of adders, each of which supports four input variables. While a specific LOR and a current object orientation are input to the first digital pipeline latch, processing for a different LOR and an earlier object orientation are stored in the second digital pipeline latch. Additionally, fully transformed coordinates from a third LOR are loaded into a third digital pipeline latch. As the banks may each complete their respective tasks under a threshold time limit, the pipelining technique permits the entire 3D transformation for the AB pair to take place in real time. Further, on-line normalization and on-line weighted histogramming are also performed in real time.

A method and apparatus for on-line DOI rebinning for LSO PET/SPECT to improve spatial resolution, for use in a hybrid Positron Emission Tomography (PET)/Single Photon Emission Computed Tomography (SPECT) system running in PET-mode. Data acquisition hardware is used to feed a detector pair coincidence event stream to an on-line rebinner. Gamma centroid location measurements are made by rastering assumed transaxial and radial head positions and the corresponding rebinning maps for optimal back-projected image resolution. Optimal positions are found by collecting a 64-bit list mode file, assuming a crystal position as the centroid for each of the heads, defining a sequence for varying the assumed positions, making the rebinning look-up tables, rebinning the list mode data, histogramming and reconstructing the image, assessing the image resolution, recording the best resolution number and the associated trial position variables, repeating these on the next trial variable set.

On-line DOI rebinning for LSO PET/SPECT spatial resolution

A coincidence transmission source serves to detect coincident activity from a radiation source. The coincidence transmission source includes a detector dedicated to collecting attenuation data. A collimated radiation source and a detector are positioned with respect to a tomography device such that only a selected strip of the imaging detector of the tomograph is illuminated such that events unrelated to the attenuation are eliminated. The coincidence transmission source includes a collimator in which is disposed a radiation source. Fiber optics are interconnected between a plurality of dedicated gamma radiation detectors and a plurality of photomultiplier tubes. The arrangement of fiber optics is designed such that the address of a particular gamma radiation detector is readily discernable while minimizing the number of PMT's required to process data accumulated by the gamma radiation detectors. In one embodiment, the attenuation point sources are disposed in a two-dimensional array to effectively minimize gamma crosstalk.

Fiber-optic encoding for dual transmission measurements in positron emission tomography

A coincidence transmission source serves to detect coincident activity from a radiation source. The coincidence transmission source includes a detector dedicated to collecting attenuation data. A collimated radiation source and a detector are positioned with respect to a tomography device such that only a selected strip of the imaging detector of the tomograph is illuminated such that events unrelated to the attenuation are eliminated. The coincidence transmission source includes a collimator in which is disposed a radiation source. An opening is defined by the collimator for exposing a selected portion of the imaging detectors of the tomograph device. Positioned behind the radiation source, relative to the imaging detectors, is the dedicated attenuation detector. The attenuation detector and collimator are designed to illuminate only a strip of the imaging detector, thereby eliminating events not of interest in the attenuation measurement. In a dual head tomograph device, one coincidence transmission source of the present invention is disposed opposite each bank of imaging detectors. The sources and the associated collimators are positioned to the side of each head at a slight angle relative to the respective head. The sources and detectors are fixed relative to the imaging heads. In order to obtain full coverage of the field of view (FOV) in the same manner as for an emission scan, the heads and sources are rotated about the center of the camera.

Coincidence transmission source

A method and apparatus for producing radioactive transmission measurements to form multi-dimensional attenuation correction data with a point source of radiation, such as required in positron emission tomography applications. This involves the passing of the point source proximate the face of each of the tomograph units for the formation of a 3-D image, or a selected portion of the tomograph units for a 2-D image. As such, attenuation data, transmission data, detector performance data, etc., can be obtained. This point source of radiation, in one embodiment, is rapidly circulated through a conduit that passes across each detector face under the influence of a transport fluid in, for example, an oscillatory motion to achieve a selected radiation field whereby calculation of transmission measurements within a body positioned within the tomograph scanner is achieved. When not being circulated, the radiation source is held within a shield. In another embodiment, the point source is a CT device. In a further embodiment, a single photon source is used in association with an ECAT ART having two oppositely disposed detector banks. One point source is provided for association with each detector bank. Each point source is capable of axial movement with respect to the detector banks, with the entire apparatus including the detector banks and the point sources being rotatable. Collimators are provided for each point source, the collimators and the point source being fixed with respect to each other, thus reducing the effects of dead-time during a transmission scan typically caused by the point source moving behind a collimator.

Method and apparatus for forming multi-dimensional attenuation

A method and apparatus for producing radioactive transmission measurements to form multi-dimensional attenuation correction data with a point source of radiation, such as required in positron emission tomography applications. This involves the passing of the point source proximate the face of a selected each of the tomograph units for the formation of a 3-D image, or a selected portion of the tomograph units for a 2-D image. As such, attenuation data, transmission data, detector performance data, etc., can be obtained. This point source of radiation, in one embodiment, is rapidly circulated through a conduit that passes across each detector face under the influence of a transport fluid in, for example, an oscillatory motion to achieve a selected radiation field whereby calculation of transmission measurements within a body positioned within the tomograph scanner is achieved. When not being circulated, the radiation source is held within a shield. Circulation of the transport fluid, typically a hydraulic fluid, is typically accomplished using a positive displacement pump. Position sensors are used to monitor the movement of the source in the conduit as well as its position within the shield. Disconnect units permit removal of the radiation source, as contained in the shield, from the system without accessing any other portions of the system. In another embodiment, the point source is a CT device.

Method and apparatus for forming multidimenstional attenuation

A method and apparatus for producing radioactive transmission measurements to form a 2-D or a 3-D image with a point source of radiation, such as required in positron emission tomography applications. This involves the passing of the point source proximate the face of a selected each of the tomograph units for the formation of a 3-D image, or a selected portion of the tomograph units for a 2-D image. As such, attenuation data, transmission data, detector performance data, etc., can be obtained. This point source of radiation is rapidly circulated through a conduit that passes across each detector face under the influence of a transport fluid in, for example, an oscillatory motion to achieve a selected radiation field whereby calculation of transmission measurements within a body positioned within the tomograph scanner is achieved. When not being circulated, the radiation source is held within a shield. Circulation of the transport fluid, typically a hydraulic fluid, is typically accomplished using a positive displacement pump. Position sensors are used to monitor the movement of the source in the conduit as well as its position within the shield. Disconnect units permit removal of the radiation source, as contained in the shield, from the system without accessing any other portions of the system.

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Knoxville, TN, United States of America

William F Jones