Picker International, Inc.

Other

Koninklijke Philips Corporation N.v.

Philips Medical Systems, Inc.

Frank C Valentino

Frank P DiFilippo

Leonard F Plut

Pieter Gerhard Roos

Michael J Petrillo

Andrew J Ivan, Jr

Robert L Zahn

Gerhard P Roos

Andrew J Ivan

John R Leichliter

Dennis C Shand

Steven E Cooke

Leonard F Plutt

An imaging system includes a set of detector modules that detect gamma rays, which have energy in a range of 40 to 140 keV and 511 keV, emitted by a radioisotope in an examination region, wherein 511 keV gamma rays are detected in singles mode in which individual 511 keV gamma rays, and not coincidence pairs of 511 keV gamma rays, are detected, an energy discriminator that bins detected gamma rays into a first energy bin corresponding to 511 keV energy gamma rays and a second energy bin corresponding to 40 to 140 keV energy gamma rays, and a reconstructor that reconstructs the 511 keV energy gamma rays thereby generating a first image of a distribution of a first radionuclide and that reconstructs the gamma rays in the one or more ranges between 40 and 140 keV thereby generating a second image of a distribution of a second radionuclide.

SPECT/PET imaging system

A diagnostic imaging system includes a rotating gantry ( ) which defines a subject receiving aperture ( ). A rotatable source of high energy penetrating radiation ( ) and a corresponding two-dimensional flat panel x-ray detector ( ) are disposed across the subject receiving aperture ( ). A plurality of nuclear detector heads ( ) are movably attached to the rotating gantry ( ) in order to detect radiation emitted by a radiopharmaceutical injected into the subject ( ). Each of the nuclear detector heads ( ) within the system includes a variable radiation shield ( ) disposed adjacent a radiation receiving face on the detector head. The diagnostic imaging system may be operated in a fluoroscopic/radiographic mode in which an isocentric x-ray beam strikes the center of the detector surface or in a volume imaging mode.

Volume cone beam acquisition on a nuclear spect system using a digital flat panel

A gamma camera includes at least one detector assembly 10. The detector assembly includes an array of photomultiplier tubes, a sheet of scintillating crystal material, a sheet of optical glass, and a matrix of mu-metal material. The mu-metal matrix defines an array of apertures corresponding to the array of photomultiplier tubes into which apertures the photomultiplier tubes are inserted. The scintillating crystal is bonded to the first surface of the optical glass. The mu-metal matrix is connected to the second surface of the sheet of optical glass using an adhesive such as an epoxy cement. By integrating the metal matrix into the structure formed by the glass sheet and the crystal, the glass sheet may be made thinner than before while the crystal is supported against possible bending and consequent fracture.

Support assembly for scintillating crystal

This invention addresses the practical implementation of PET imaging capability on a conventional gamma camera. The primary subject of this invention is the addition of a real time processor to perform the rebinning calculations and other on-the-fly calculations and procedures to make PET imaging on a gamma camera more practical. The rebinning or transformation operation described above is performed on-the-fly as each event pair is detected with an event throughput rate sufficient for clinical applications. This transformation process is performed by a chain of digital signal processing subsystems (or similar real time processors), with the resultant transformed data stored in a memory subsystem until a sufficient number of events have been received to produce an image of acceptable quality.

Real time pet imaging processor for a single photon gamma camera

To calibrate a nuclear camera, the scintillation crystal (10) is irradiated with a uniform flood source (34). Scintillation events cause corresponding electrical pulses from photomultiplier tubes (12) that are optically coupled to the scintillation crystal. A selection circuit (40) compares (42) the amplitude or energy of pulses at each coordinate with a median energy and divides the pulses to generate a higher energy image (44) and a lower energy image (46). When the higher and lower energy images are subtracted (50) regions of the difference image (52) with high count densities identify a photomultiplier tube for gain adjustment. A gain adjustment circuit (60) monitors the amplitude of the electrical pulses and the number of pulses with each amplitude from the selected photomultiplier tube to generate a raw data energy distribution curve (FIG. 3). The energy distribution curve is smoothed (70) and the first derivative is taken (72). The curve is filtered (74) to isolate a preselected energy region. The curve is analyzed (92) to determine an energy value corresponding to a centroid (94) of the filtered first derivative curve. The centroid energy value is compared (96) with the centroid energy value from a preprogrammed table (32). The deviation between the calculated and looked-up centroid energy addresses a look-up table (98) which retrieves the appropriate adjustment to the selected photomultiplier tube. Each adjustment of the photomultiplier tube is stored in a gain adjustment history memory (110).

Technique for balancing anger cameras using an externally irradiated

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Solon, OH, United States of America

Frank C Valentino