Siemens Medical Solutions Usa, Inc.

Fred E Macciocchi

James Frank Caruba

Ronald E Malmin

Sharon Xiaorong Wang

James T Chapman

Trudy Dayle Rempel

George William Dailey

John P Valenta

A quality control system and method are provided for troubleshooting and performance testing of detectors in a Gamma camera that includes a field programmable gate array for forming digital words to be converted to a pulse, a test pattern generator for storing the digital words, a digital analog converter for converting the digital words into an analog voltage, an amplifier for amplifying and applying the analog voltage, and an analog multiplexor for accepting the analog voltage. The Gamma camera comprises a collimator, a scintillation crystal, a light guide, a photomultiplier tube, and an electronic circuit.

Gamma camera calibration and diagnosis using pulse injection

In some preferred embodiments, an apparatus is provided that facilitates correction, such as, e.g., linearity correction, in imaging devices, such as, e.g., scintillation cameras. In preferred embodiments, a mask is implemented that can produce images for locating the actual position of a nuclear event based on its apparent position with high accuracy and reliability. In the preferred embodiments, the mask includes a non-uniform array of apertures that can achieve this goal.

Imaging devices and methods employing masks with a non-uniform grid of pinhole apertures

A high voltage distribution system and method for use with a cathode of a radiographic sensor device of a radiographic imaging apparatus are provided. The distribution system includes an insulated conductor formed on a first detector portion of the radiographic sensor device and communicating a high voltage to the cathode. The distribution system further includes an intermediate conduction portion communicating with the insulated conductor. The intermediate conduction portion includes a contact surface. The distribution system further includes a interconnect extending from a second portion of the radiographic sensor device. The separable interconnect communicates with an electrical voltage source and is positioned to come into contact with the intermediate conduction portion when the first detector portion of the radiographic sensor device is assembled to the second signal processing portion.

High voltage distribution for a radiographic sensor device

A circuit arrangement is provided which has the advantage of limiting the magnitude of the current to a transimpedance amplifier (TIA) circuit or a current to voltage converter during an overdrive condition, thereby preventing an amplifier of the TIA circuit from non-linear operation and from outputting high output currents. The circuit arrangement further prevents the generation of thermal tails which may cause the loss of data in memory circuits. The circuit arrangement limits the magnitude of the current to the TIA circuit during the overdrive condition by utilizing a current limiter circuit having a Schottky bridge. The Schottky bridge provides an open circuit arrangement between the TIA circuit and a current source when the overdrive condition occurs.

Circuit arrangement having a transimpedance amplifier connected to a current limiter circuit

A positron imaging system includes a pair of scintillation detectors for detecting a pair of gamma rays produced by annihilation of a positron within a distribution field, such as within a patient. An energy level determination circuit determines the energy levels of the detected gamma rays, and timing circuits determine whether the gamma rays have been detected by the scintillation detectors within a predetermined time interval. Only if the determined energy levels of each of the pair of gamma rays meet predetermined magnitude requirements and detection of the pair of gamma rays has occurred within the predetermined time interval, are signals corresponding to said gamma rays inputted to processing circuitry for calculating the spatial location of the positron. According to a further aspect of the invention, a circuit for separating piled-up gamma ray events includes a delay and a controllable attenuator for delaying and simultaneously attenuating a signal outputted by the detector, and a comparator for comparing the delayed signal with the attenuated signal, to thereby output separate electrical pulses representing the separate events.

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Huntley, IL, United States of America

Fred E Macciocchi