Patent application number | Description | Published |
20080290282 | Concurrent DC-Coupled Anode and Dynode Readout Scheme For PET Block Detectors - A scintillation detector including one or more photomultiplier tubes, a scintillation block optically attached to the photomultiplier tubes, and a DC-coupled bleeder circuit combining outputs of dynodes of the photomultipliers to provide a DC-coupled dynode output together with a DC-coupled anode output of the photomultiplier tubes. The DC-coupled bleeder circuit includes a RF transformer. A positive high voltage supply also can be used together with a DC-coupled bleeder circuit for the anode outputs. | 11-27-2008 |
20090072151 | Parameter Adjustment for Medical Device - A medical device with a high voltage connection line for carrying a high DC supply voltage has a control unit generating said high DC supply voltage which is fed through a first AC block unit to said high voltage connection line and generating a digital control signal fed through a first AC coupling unit to said high voltage connection line, and a remotely located unit a second AC block unit coupled to said high voltage connection line for receiving said high DC supply voltage and a second AC coupling unit coupled to said high voltage connection line for receiving said digital control signal. | 03-19-2009 |
20090108206 | MR-Compatible Blood Sampling System For PET Imaging Applications in Combined PET/MR Imaging System - An automated blood sampling system for PET imaging applications that can be operated in or very near to the field of view (FOV) of an MR scanner, such as in a combined MR/PET imaging system. A radiation detector uses APDs (avalanche photo-diodes) to collect scintillation light from crystals in which the positron-electron annihilation photons are absorbed. The necessary gamma shielding is made from a suitable shielding material, preferably tungsten polymer composite. Because the APDs are quite small and are magnetically insensitive, they can be operated in the strong magnetic field of an MR apparatus without disturbance. | 04-30-2009 |
20100065746 | SYSTEMS AND METHODS FOR CALIBRATING A SILICON PHOTOMULTIPLIER-BASED POSITRON EMISSION TOMOGRAPHY SYSTEM - A representative positron emission tomography (PET) system includes a positron emission tomography detector having one or more silicon photomultipliers that output silicon photomultipliers signals. The PET system further includes a calibration system that is electrically coupled to the silicon photomultipliers. The calibration system determines a single photoelectron response of the silicon photomultipliers signals and adjusts a gain of the silicon photomultipliers based on the single photoelectron response. | 03-18-2010 |
20100066426 | BASELINE RESTORE BASED ON DIODE STAR CONFIGURATION AND TRANSFORMER COUPLING - A simple, low cost circuit with only passive components, and thus low power consumption, is provided for baseline restoration of an AC coupled signal. The circuit includes a passive network of diodes arranged in a star configuration and an RF-transformer. A differential signal strategy may be employed by including a differential amplifier at the input and output of the passive network. | 03-18-2010 |
20100067001 | OPTICAL MASK FOR DETECTOR OPTIMIZATION - An optical mask positioned on a scintillator array. The optical mask includes a reflective layer. One or more windows can be positioned on the surface of optical mask. | 03-18-2010 |
20100074396 | MEDICAL IMAGING WITH BLACK SILICON PHOTODETECTOR - Medical imaging may be accomplished with a high photoconductive gain at a relatively low operating voltage by employing a black silicon photodetector and integrating CMOS components with elements of the photodetector. | 03-25-2010 |
20100076300 | DATA PROCESSING SYSTEM FOR MULTI-MODALITY IMAGING - 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. | 03-25-2010 |
20110074426 | Detector module for an emission tomography scanner - An emission tomography detector module and an emission tomography scanner are disclosed. In at least one embodiment, the emission tomography detector modules includes a scintillator to capture an photon, the scintillator emitting a scintillating light on capturing the photon; a first type of solid-state photodetector to detect the scintillating light; and a second type of solid-state photodetector to detect the scintillating light, wherein the first type of solid-state photodetector and the second type of solid-state photodetector are different with respect to a detecting property. | 03-31-2011 |
20110147567 | SiPM Photosensor With Early Signal Digitization - The present invention is a Silicon PhotoMulitplier comprising a plurality of photon detection cell clusters each comprising a plurality of avalanche photodiodes connected in parallel, so that the output of each avalanche photodiode is summed together and applied to a cell cluster output. Each of the plurality of cell cluster outputs is connected to one of a plurality of cluster readout circuits, each of which includes an analog to digital converter that converts an analog representation of the total energy received by a photon detection cell cluster to a digital energy signal. A SiPM Pixel reader circuit is connected to the plurality of cluster readout circuits and configured to generate an overall pixel output by digital processing the plurality of digital energy signals received from the plurality of photon detection cell clusters by way of the plurality of cluster readout circuits. The SIPM pixel reader circuit also receives digital signals representative of timing triggers and the total energy received by a specific photon detection cell cluster and generates an overall SiPM energy signal and overall timing trigger in response to the signals received from the plurality of cluster readout circuits. | 06-23-2011 |
20120112083 | High Density, Proportional-Mode, APD Arrays for Individual Scintillator Readout in PET Applications - The present invention is a photodetector including improved photosensors configured of an array of small (sub-millimeter) high-density avalanche photodiode cells utilized to readout a single scintillator. Each photosensor comprises a plurality of avalanche photodiodes cells arranged in an (n×n) array of avalanche photodiode cells (where, n>1) that are coupled to a single scintillation crystal. The overall (n×n) array area as the photosensor is the same as the area of a face of the scintillator and each avalanche photodiode cell has a surface area that is not greater than one square millimeter. The photosensor is also configured to facilitate reading the output of each avalanche photodiode cell in the array. By reading out each small avalanche photodiode cell independently, the noise and capacitance are minimized and thereby provide a more accurate determination of energy and timing. | 05-10-2012 |
20120212355 | Encoding for Nuclear Medical Imaging Block Detectors - Signals generated by radiation sensors can be encoded to reduce the number of cables needed to transport information from a nuclear imaging apparatus to a processor for reconstruction. For example, signals from 16 radiation sensors can be encoded into three signals: T (top), L (left), and E (energy). This method of encoding signals can be capable of substantially reducing the number of signals, thereby reducing costs. In addition, reducing the number of signals could improve system timing performance by eliminating cable time-skew and facilitate the filter design by downgrading the circuit accuracy requirements such as group-delay error and filter signal skews. | 08-23-2012 |
20130009047 | Energy Correction for One-To-One Coupled Radiation Detectors Having Non-Linear Sensors - Systems and methods for correcting output signals from non-linear photosensors, specifically silicon photomultipliers (SiPMs). SiPMs are used in a PET detector to readout light emissions from LSO scintillator crystals. The non-linear output of the SiPM can distort and compress the energy spectrum which is crucial in PET imaging. The non-linearity effect for inter-crystal scattered events can place an energy event outside of the PET detector energy window, resulting in a rejected event. Systems and methods to correct the SiPM non-linearity for inter-crystal scattered events, so as to be able to obtain the proper energy event and produce an accurate medical image, are disclosed. | 01-10-2013 |
20130009063 | System and Method for Improving Detection of Gamma Interactions in a Positron Emission Tomography System - A system and method are provided for determining the onset of gamma interactions for positron emission tomography (PET) imaging more accurately than with existing techniques. The timing of a sequence of primary trigger events is obtained and used to determine a weighted combination, which mixes the timing information from the various primary trigger events to compute an overall event trigger timing with improved time resolution. Numerical simulations demonstrate that the invention improves time resolution by approximately 10% over state-of-the-art methods. This improved time resolution directly benefits the imaging performance of the PET scanner, especially in time-of-flight (TOF) mode, where a high time resolution directly translates to a reduction in image noise at the same dose—or, alternatively, a reduction of dose to the patient or scan time for the same image quality. | 01-10-2013 |
20130009267 | Providing Variable Cell Density and Sizes in a Radiation Detector - An apparatus and method to decrease light saturation in a photosensor array and increase detection efficiency uses a light distribution profile from a scintillator-photodetector geometry to configure the photosensor array to have a non-uniform sensor cell pattern, with varying cell density and/or varying cell size and shape. A solid-state photosensor such as a SiPM sensor having such a non-uniform cell structure realizes improved energy resolution, higher efficiency and increased signal linearity. In addition the non-uniform sensor cell array can have improved timing resolution due to improvements in statistical fluctuations. A particular embodiment for such photosensors is in PET medical imaging. | 01-10-2013 |
20130062525 | Positron Emission Tomography Block Detector Interconnect - Using standard or “off the shelf” cable to interconnect between the PET block detector and the detector circuit may save substantial costs given the number of PMTs in a PET system. Given space constraints, simple maintenance with reduced risk of disturbing cabling is desired, making ongoing use of standard cabling without adding further cabling desired. To implement digital gain control, a further communication is provided between the PET detector block and the detector circuit. Since the standard cable may not have additional wires for such communications and to reduce timing degradation, the PMT signals are combined, such as generating position and energy signals at the PET detector block. The four PMT signals are reduced to three signals without reduction in function, allowing a fourth twisted pair of wires in a CAT5 cable to be used for digital gain control. | 03-14-2013 |
20130087710 | Trigger Methods in Nuclear Medical Imaging - Disclosed herein are a system, method, and computer-readable storage medium for determining a time pickoff for both digital and analog photomultiplier circuits. Rather than basing time pickoff on the leading edge of a photomultiplier signal crossing a threshold or the first signal from a digital photomultiplier, a method for more accurate time calculations is disclosed. The system searches for peak values associated with the signal using differentiation, peak hold searching, and Gaussian distributions. Based on these calculations and comparisons, a more accurate time pickoff is determined. | 04-11-2013 |
20130184559 | Magnetic Resonance Imaging Compatible Positron Emission Tomography Detector - A compact magnetic resonance imaging compatible positron emission tomography detector. The detector has integrated mechanical and electrical subcomponents. The detector uses a cooling channel which does not interfere with magnetic resonance imaging. The layout and selection of electrical subcomponents of the detector, along with a magnetic resonance compatible cooling strategy, enables the detector to function in a magnetic resonance imaging environment. | 07-18-2013 |
20150069250 | CMOS SPAD Array with Mixed Timing Pick-Off for Time-of-Flight Positron Emission Tomography - Timing pick-off is provided in time-of-flight positron emission using digital output photo sensors (e.g., SPAD or dSiPM). The timing-to-digital converter (TDC) is replaced for timing detection with a mixed analog and digital timing pick-off (MTP) where a processor determines the timing from an output of the MTP. The digital SPAD or dSiPM output is summed into an analog waveform, allowing for triggering based on signal statistics or other than at a particular number of discrete detections. The trigger is used by the processor to extrapolate the time of occurrence without an integrated TDC. | 03-12-2015 |