The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Carlo Fiorini - One of the best experts on this subject based on the ideXlab platform.
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First results of the HICAM Anger Camera
2009 IEEE Nuclear Science Symposium Conference Record (NSS MIC), 2009Co-Authors: Carlo Fiorini, A. Longoni, P. Busca, Alberto Gola, R. Peloso, Andrea Abba, A. Geraci, G. Padovini, Heike Soltau, Brian HuttonAbstract:We are developing a new Anger Camera for nuclear imaging in the framework of the HICAM (HIgh resolution Camera) project supported by European Community. The Camera is foreseen to be employed in applications where high-position resolution (~ 1 mm intrinsic spatial resolution) and Camera compactness are of primary concern. The Camera is based on the use of monolithic arrays of Silicon Drift Detectors (SDDs), each one with a JFET integrated in the detector chip. In this work we present the results of the characterization of a first prototype of the Camera (1/4 of the final expected active area), composed by 25 SDDs of 1cm2 each in a 5×5 format. The module is read-out by a single 25-channels ASIC. The prototype of the Camera is presented in this work together with the results of the gamma-ray imaging characterization.
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Optimum real-time reconstruction of Gamma events for high resolution Anger Camera with the use of GPGPU
2009 IEEE Nuclear Science Symposium Conference Record (NSS MIC), 2009Co-Authors: Stefano Pedemonte, Andrea Abba, Alberto Gola, Carlo FioriniAbstract:Aim of the HICAM project is to build a new, compact Gamma-ray imager with a submillimeter spatial resolution, based on the Anger Camera principle. The system is composed of a detection module with frontend ASICs, an acquisition board and a host PC, where real-time data processing and image reconstruction is implemented. The detector is based on an array of 100 Silicon Drift Detectors (SDDs) of 1 cm2 each in a 10 ×10 cm2 format, coupled to a single scintillator crystal. Position of the interaction with the crystal and energy of the incident radiation are obtained through the use of a MLE algorithm, that optimally exploits the information obtained from the detectors. Moreover it is possible to modify the algorithm in order to determine the depth of interaction of the Gamma photon inside the crystal. The MLE algorithm, on the other hand, requires a large amount of calculations per event. In order to process the events in real-time we have implemented the MLE algorithm on a GPGPU, obtaining a processing rate of 150000 events/second, considering a FOV of 512 ×512 ×10 points (calculation of the z coordinate is performed). In the paper we discuss the derivation of the algorithm, its performance for what concerns spatial resolution and distortion, and the speed of its implementation on the GPGPU.
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HICAM: Development of a high-resolution Anger Camera for nuclear medicine
2008 IEEE Nuclear Science Symposium Conference Record, 2008Co-Authors: Carlo Fiorini, A. Longoni, Alberto Gola, R. Peloso, A. Geraci, G. Padovini, Brian Hutton, Peter Lechner, L. Struder, Kjell ErlandssonAbstract:A new Anger Camera for nuclear imaging is under development in the framework of the HICAM (HIgh resolution Camera) project supported by European Community. It is foreseen to be employed in applications where high-position resolution and Camera compactness are of primary concern. Thanks to a higher intrinsic resolution (≪1mm), an advanced collimator technology and the Camera compactness, it would be possible to achieve an overall improvement of imaging performance of ∼ 2.5 mm (at an imaging distance of 5 cm). The Silicon Drift Detectors (SDDs) used in this Camera have recently shown to be a competitive device for the readout of scintillator with respect to conventional photodetectors like photomultiplier tubes, thanks to their high quantum efficiency and low electronics noise. HICAM Camera will be composed by 100 SDDs of 1cm2 each in a 10 cm × 10 cm format. The modular structure of this Camera, as well as the preliminary results of the development of its sub-systems, is presented in this work.
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Present and future Anger Cameras based on Silicon Drift Detectors
2007 IEEE Nuclear Science Symposium Conference Record, 2007Co-Authors: Carlo Fiorini, A. Longoni, Alberto Gola, R. Peloso, Peter Lechner, L. Struder, Alan OwensAbstract:Silicon drift detectors (SDDs) have recently shown to be a competitive device for the readout of scintillator with respect to conventional photodetectors like photomultiplier tubes, thanks to their high quantum efficiency and low electronics noise. In particular, arrays of SDDs could represent an interesting photodetector to be employed in the development of Anger Cameras with high position resolution. Recently, we have developed the DRAGO Camera, which is a high-resolution Anger Camera based on a monolithic array of 77 SDDs, with an active area of 6.7 cm2, coupled to a scintillator crystal. The performances achieved in gamma-ray imaging using this Camera are first reported in this work. According to the achieved results, we are now designing a new Anger Camera, in the framework of the HICAM project, composed by 100 SDDs of 1 cm2 each in a 10times10 cm2 format. This Camera is foreseen to be employed in application mainly for human imaging where high-position resolution and Camera compactness are of primary interest. The main issues of the design of this Camera as well as the results of Montecarlo simulations of its performances are presented in this work. As a basic unit for this Camera, we have experimentally characterized the electronics noise and gamma-ray performances, when coupled to a scintillator, of a SDD of 1 cm2 of active area. This device shows excellent performances in terms of electronics noise with moderate cooling achieved by a Peltier element.
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The electronics readout and the DAQ system of the DRAGO Anger Camera
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2006Co-Authors: Alberto Gola, Carlo Fiorini, Matteo Porro, M. ZanchiAbstract:Abstract The aim of the DRAGO project, supported by Italian INFN, is the development of a high-resolution, compact γ -ray imager, based on the Anger Camera principle. In this configuration, the light generated by a unique scintillator is read by an array of 77 Silicon Drift Detectors. In order to locate the position of interaction of the photon inside the scintillator, it is necessary to make an amplification and filtering of the detector signals followed by a processing of the acquired data. The electronics readout and processing system can be divided in two separate parts: the analog front end and the DAQ board. The analog front end is composed of 80 readout channels divided in 10 CMOS chips, produced in the 0.35 μm AMS technology, each one processing 8 channels. Each analog channel of the circuit includes a low-noise preamplifier, a sixth-order semigaussian shaping amplifier with four selectable peaking times from 1.8 μs up to 6 μs, a peak stretcher and a baseline holder. The energy resolution measured using a single channel of the chip with a Silicon Drift Detector Droplet (SD 3 ) is of 128 eV FWHM at 6 keV with the detector cooled at −20 °C. The 8 analog channels of the chip are multiplexed to a single analog output and fed to the acquisition system. For each γ event, this system performs the A/D conversion of all the signals of the array and sends them to a host PC, where the position reconstruction algorithm is executed. The DAQ board contains 10 ADCs, each one dedicated to a single ASIC of the analog section and having a resolution of 13 bit (ENOB). The burst conversion rate of the 10 ADCs together is 50 Ms/s resulting in a dead time of about 2 μs/event. The converted data are stored in a FIFO memory, for buffering, and then are transferred to the host PC via a USB 2.0 interface, which allows an event rate of more than 40k events/s for the whole Anger Camera, compatible with the application.
A. Morozov - One of the best experts on this subject based on the ideXlab platform.
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SiPM-based neutron Anger Camera with auto-calibration capabilities
Journal of Instrumentation, 2019Co-Authors: A. Morozov, J. Marcos, L.m.s. Margato, Damien Roulier, V. N. SolovovAbstract:We present characterization results of a neutron Anger Camera based on a lithium-6 loaded cerium activated silicate glass scintillator (33.3 × 33.3 × 1 mm3) and an array of 64 silicon photomultipliers. Reconstruction of the scintillation events is performed with a statistical method, implemented on a graphics processing unit (GPU). We demonstrate that the light response model of the detector can be obtained from flood irradiation calibration data using an unsupervised iterative procedure. The useful field of view is 28 × 28 mm2. The spatial resolution measured at 2.5 A neutron beam is better than 0.6 mm FWHM and the energy resolution at the neutron peak is 11%.
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ANTS2 package: simulation and experimental data processing for Anger Camera type detectors
Journal of Instrumentation, 2016Co-Authors: A. Morozov, V. N. Solovov, R. Martins, F. Neves, V. Domingos, V. ChepelAbstract:ANTS2 is a simulation and data processing package developed for position sensitive detectors with Anger Camera type readout. The simulation module of ANTS2 is based on ROOT package from CERN, which is used to store the detector geometry and to perform 3D navigation. The module is capable of simulating particle sources, performing particle tracking, generating photons of primary and secondary scintillation, tracing optical photons and generating photosensor signals. The reconstruction module features several position reconstruction methods based on the statistical reconstruction algorithms (including GPU-based implementations), artificial neural networks and k-NN searches. The module can process simulated as well as imported experimental data containing photosensor signals. A custom library for B-spline parameterization of spatial response of photosensors is implemented which can be used to calculate and parameterize the spatial response of a detector. The package includes a graphical user interface with an extensive set of configuration, visualization and analysis tools. ANTS2 is being developed with the focus on the iterative (adaptive) reconstruction of the detector response using flood field irradiation data. The package is implemented in C++ programming language and it is a multiplatform, open source project.
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Adaptive algorithms of position and energy reconstruction in Anger-Camera type detectors: experimental data processing in ANTS
Journal of Instrumentation, 2013Co-Authors: A. Morozov, I. Defendi, Ralf Engels, F.a.f. Fraga, M.m.f.r. Fraga, B. Guerard, M. Jurkovic, Günter Kemmerling, A. Gongadze, G. ManzinAbstract:The software package ANTS (Anger-Camera type Neutron detector: Toolkit for Simulations), developed for simulation of Anger-type gaseous detectors for thermal neutron imaging was extended to include a module for experimental data processing. Data recorded with a sensor array containing up to 100 photomultiplier tubes (PMT) or silicon photomultipliers (SiPM) in a custom configuration can be loaded and the positions and energies of the events can be reconstructed using the Center-of-Gravity, Maximum Likelihood or Least Squares algorithm. A particular strength of the new module is the ability to reconstruct the light response functions and relative gains of the photomultipliers from flood field illumination data using adaptive algorithms. The performance of the module is demonstrated with simulated data generated in ANTS and experimental data recorded with a 19 PMT neutron detector. The package executables are publicly available at http://coimbra.lip.pt/~andrei/
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ANTS — a simulation package for secondary scintillation Anger-Camera type detector in thermal neutron imaging
Journal of Instrumentation, 2012Co-Authors: A. Morozov, I. Defendi, Ralf Engels, F.a.f. Fraga, M.m.f.r. Fraga, B. Guerard, M. Jurkovic, Günter Kemmerling, G. Manzin, L.m.s. MargatoAbstract:A custom and fully interactive simulation package ANTS (Anger-Camera type Neutron detector: Toolkit for Simulations) has been developed to optimize the design and operation conditions of secondary scintillation Anger-Camera type gaseous detectors for thermal neutron imaging. The simulation code accounts for all physical processes related to the neutron capture, energy deposition pattern, drift of electrons of the primary ionization and secondary scintillation. The photons are traced considering the wavelength-resolved refraction and transmission of the output window. Photo-detection accounts for the wavelength-resolved quantum efficiency, angular response, area sensitivity, gain and single-photoelectron spectra of the photomultipliers (PMTs). The package allows for several geometrical shapes of the PMT photocathode (round, hexagonal and square) and offers a flexible PMT array configuration: up to 100 PMTs in a custom arrangement with the square or hexagonal packing. Several read-out patterns of the PMT array are implemented. Reconstruction of the neutron capture position (projection on the plane of the light emission) is performed using the center of gravity, maximum likelihood or weighted least squares algorithm. Simulation results reproduce well the preliminary results obtained with a small-scale detector prototype. ANTS executables can be downloaded from http://coimbra.lip.pt/~andrei/.
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ants a simulation package for secondary scintillation Anger Camera type detector in thermal neutron imaging
Journal of Instrumentation, 2012Co-Authors: A. Morozov, I. Defendi, Ralf Engels, F.a.f. Fraga, M.m.f.r. Fraga, B. Guerard, M. Jurkovic, Günter Kemmerling, G. Manzin, L.m.s. MargatoAbstract:A custom and fully interactive simulation package ANTS (Anger-Camera type Neutron detector: Toolkit for Simulations) has been developed to optimize the design and operation conditions of secondary scintillation Anger-Camera type gaseous detectors for thermal neutron imaging. The simulation code accounts for all physical processes related to the neutron capture, energy deposition pattern, drift of electrons of the primary ionization and secondary scintillation. The photons are traced considering the wavelength-resolved refraction and transmission of the output window. Photo-detection accounts for the wavelength-resolved quantum efficiency, angular response, area sensitivity, gain and single-photoelectron spectra of the photomultipliers (PMTs). The package allows for several geometrical shapes of the PMT photocathode (round, hexagonal and square) and offers a flexible PMT array configuration: up to 100 PMTs in a custom arrangement with the square or hexagonal packing. Several read-out patterns of the PMT array are implemented. Reconstruction of the neutron capture position (projection on the plane of the light emission) is performed using the center of gravity, maximum likelihood or weighted least squares algorithm. Simulation results reproduce well the preliminary results obtained with a small-scale detector prototype. ANTS executables can be downloaded from http://coimbra.lip.pt/~andrei/.
L.m.s. Margato - One of the best experts on this subject based on the ideXlab platform.
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SiPM-based neutron Anger Camera with auto-calibration capabilities
Journal of Instrumentation, 2019Co-Authors: A. Morozov, J. Marcos, L.m.s. Margato, Damien Roulier, V. N. SolovovAbstract:We present characterization results of a neutron Anger Camera based on a lithium-6 loaded cerium activated silicate glass scintillator (33.3 × 33.3 × 1 mm3) and an array of 64 silicon photomultipliers. Reconstruction of the scintillation events is performed with a statistical method, implemented on a graphics processing unit (GPU). We demonstrate that the light response model of the detector can be obtained from flood irradiation calibration data using an unsupervised iterative procedure. The useful field of view is 28 × 28 mm2. The spatial resolution measured at 2.5 A neutron beam is better than 0.6 mm FWHM and the energy resolution at the neutron peak is 11%.
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ANTS — a simulation package for secondary scintillation Anger-Camera type detector in thermal neutron imaging
Journal of Instrumentation, 2012Co-Authors: A. Morozov, I. Defendi, Ralf Engels, F.a.f. Fraga, M.m.f.r. Fraga, B. Guerard, M. Jurkovic, Günter Kemmerling, G. Manzin, L.m.s. MargatoAbstract:A custom and fully interactive simulation package ANTS (Anger-Camera type Neutron detector: Toolkit for Simulations) has been developed to optimize the design and operation conditions of secondary scintillation Anger-Camera type gaseous detectors for thermal neutron imaging. The simulation code accounts for all physical processes related to the neutron capture, energy deposition pattern, drift of electrons of the primary ionization and secondary scintillation. The photons are traced considering the wavelength-resolved refraction and transmission of the output window. Photo-detection accounts for the wavelength-resolved quantum efficiency, angular response, area sensitivity, gain and single-photoelectron spectra of the photomultipliers (PMTs). The package allows for several geometrical shapes of the PMT photocathode (round, hexagonal and square) and offers a flexible PMT array configuration: up to 100 PMTs in a custom arrangement with the square or hexagonal packing. Several read-out patterns of the PMT array are implemented. Reconstruction of the neutron capture position (projection on the plane of the light emission) is performed using the center of gravity, maximum likelihood or weighted least squares algorithm. Simulation results reproduce well the preliminary results obtained with a small-scale detector prototype. ANTS executables can be downloaded from http://coimbra.lip.pt/~andrei/.
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ants a simulation package for secondary scintillation Anger Camera type detector in thermal neutron imaging
Journal of Instrumentation, 2012Co-Authors: A. Morozov, I. Defendi, Ralf Engels, F.a.f. Fraga, M.m.f.r. Fraga, B. Guerard, M. Jurkovic, Günter Kemmerling, G. Manzin, L.m.s. MargatoAbstract:A custom and fully interactive simulation package ANTS (Anger-Camera type Neutron detector: Toolkit for Simulations) has been developed to optimize the design and operation conditions of secondary scintillation Anger-Camera type gaseous detectors for thermal neutron imaging. The simulation code accounts for all physical processes related to the neutron capture, energy deposition pattern, drift of electrons of the primary ionization and secondary scintillation. The photons are traced considering the wavelength-resolved refraction and transmission of the output window. Photo-detection accounts for the wavelength-resolved quantum efficiency, angular response, area sensitivity, gain and single-photoelectron spectra of the photomultipliers (PMTs). The package allows for several geometrical shapes of the PMT photocathode (round, hexagonal and square) and offers a flexible PMT array configuration: up to 100 PMTs in a custom arrangement with the square or hexagonal packing. Several read-out patterns of the PMT array are implemented. Reconstruction of the neutron capture position (projection on the plane of the light emission) is performed using the center of gravity, maximum likelihood or weighted least squares algorithm. Simulation results reproduce well the preliminary results obtained with a small-scale detector prototype. ANTS executables can be downloaded from http://coimbra.lip.pt/~andrei/.
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ANTS: A simulation package for gas scintillation Anger Camera in thermal neutron imaging
2011 IEEE Nuclear Science Symposium Conference Record, 2011Co-Authors: A. Morozov, I. Defendi, Ralf Engels, F.a.f. Fraga, M.m.f.r. Fraga, B. Guerard, M. Jurkovic, Günter Kemmerling, G. Manzin, L.m.s. MargatoAbstract:A gas scintillation Anger Camera for thermal neutron imaging is being developed in the frame of the NMI3 FP7 Project 226507 collaboration. The detection medium is a high pressure gas mixture of 3He and CF 4 . An array of photomultiplier tubes (PMTs) registers photons of the CF 4 the PMTs. Several secondary scintillation generated in the electron avalanches at the MSGC (MicroStrip Gas Chamber) plate. The detector is expected to have sub-millimeter spatial resolution, high counting rate (up to 1 MHz) and good (>50%) detection efficiency. A custom and fully interactive Monte Carlo simulation package (ANTS: Anger Camera Neutron detector Toolkit for Simulations) was developed to optimize the design of the detector in order to reach the highest possible spatial resolution. The simulation code accounts for all relevant physical processes in the gas: neutron capture, energy deposition, electron drift, electron multiplication and secondary scintillation. Individual photons are tracked through the gas and the output window (wavelength-resolved refraction and transmission are implemented). Photo-detection accounts for the angular response, active area non-uniformity, gain and single-photon spectra of the PMTs. Several PMT read-out patterns and localization algorithms are implemented in the package. The results of simulations reproduce well the preliminary results obtained with small-scale detector prototypes.
Neal H. Clinthorne - One of the best experts on this subject based on the ideXlab platform.
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Statistical performance evaluation and comparison of a Compton medical imaging system and a collimated Anger Camera for higher energy photon imaging.
Physics in medicine and biology, 2008Co-Authors: Li Han, S.s. Huh, W. Leslie Rogers, Neal H. ClinthorneAbstract:In radionuclide treatment, tumor cells are primarily destroyed by charged particles emitted by the compound while associated higher energy photons are used to image the tumor in order to determine radiation dose and monitor shrinkage. However, the higher energy photons are difficult to image with conventional collimated Anger Cameras, since a tradeoff exists between resolution and sensitivity, and the collimator septal penetration and scattering is increased due to the high energy photons. This research compares imaging performance of the conventional Anger Camera to a Compton imaging system that can have improved spatial resolution and sensitivity for high energy photons because this tradeoff is decoupled, and the effect of Doppler broadening at higher gamma energies is decreased. System performance is analyzed by the modified uniform Cramer–Rao bound (M-UCRB) algorithms based on the developed system modeling. The bound shows that the effect of Doppler broadening is the limiting factor for Compton Camera performance for imaging 364.4 keV photons emitted from 131I. According to the bound, the Compton Camera outperforms the collimated system for an equal number of detected events when the desired spatial resolution for a 26 cm diameter uniform disk object is better than 12 mm FWHM. For a 3D cylindrical phantom, the lower bound on variance for the collimated Camera is greater than for the Compton imaginer over the resolution range from 0.5 to 2 cm FWHM. Furthermore, the detection sensitivity of the proposed Compton imaging system is about 15–20 times higher than that of the collimated Anger Camera.
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Performance comparison and system modeling of a compton medical imaging system and a collimated Anger Camera
2008 IEEE Nuclear Science Symposium Conference Record, 2008Co-Authors: Li Han, Neal H. ClinthorneAbstract:The objective of this research is to compare performance of a well modeled dual-planar silicon-based Compton imaging system with that of a collimated Anger Camera for imaging higher energy photons emitted from 131I using statistical methods. The analysis uses modified uniform Cramer-Rao bound algorithms we developed and verified along with Monte Carlo calculations and system modeling. Calculations show that the effect of Doppler broadening is the limiting factor for Compton Camera performance for imaging 364.4keV photons emitted from 131I. The performance of the two systems was compared and analyzed by simulating a two dimensional disk with uniform activity for the same number of detected events. The performance of the proposed Compton imaging system is superior to the collimated Anger Camera especially as the desired spatial resolution is better than 12mm FWHM. The ratio of the lower bounds for the two systems at 5mm and 10mm desired point source response is 1000 and 15, respectively in favor of the Compton device. Moreover, the detection sensitivity of the proposed Compton imaging system is 15–20 times higher than the collimated Anger Camera.
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Statistical performance evaluation and system modeling for a Compton medical imaging system for higher energy photon imaging
2008 IEEE Nuclear Science Symposium Conference Record, 2008Co-Authors: Li Han, Neal H. ClinthorneAbstract:The objective of this research is to study the performance of a dual-planar silicon/Anger Camera based Compton imaging system for imaging higher energy photons emitted from 131-I using, and compare it with a conventional collimated Anger Camera. The Compton imaging system is a potentially effective medical imaging device for monitoring radionuclide cancer treatments that can obtain greatly improved performance in both detection efficiency and spatial resolution for higher energy photons (e.g., 364keV) over conventionally collimated Anger Cameras. The Compton imaging system decouples the tradeoff between spatial resolution and detection efficiency inherent to absorbing collimation. System performance is primarily determined by Doppler broadening, energy resolution and spatial resolution of the scattering and absorbed detectors (in addition to the Compton image formation process). In the study, the effective system model of the Compton imaging system was developed considering all factors involved in the Compton process including above three primary uncertainties. Based on the system model, the system performance and comparison were analyzed using the modified uniform Cramer-Rao bound we developed and verified along with the Monte Carlo calculation. From the illustrated bound curves that compare the effect of silicon detector energy resolution and system spatial resolution by simulating a 2D disk having uniform activity, the limiting factor is Doppler broadening for Compton Camera performance at 364 keV. Our predictions show that performance of the proposed Compton imaging system is superior to the collimated Anger Camera especially as the desired image resolution is better than the “natural” resolution of the conventional collimator.
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High countrate Anger Camera design for electronically collimated SPECT
IEEE Symposium Conference Record Nuclear Science 2004., 1Co-Authors: S.s. Huh, Li Han, Neal H. Clinthorne, W.l. Rogers, L. Zhang, K. Subramaniam, S.-j. ParkAbstract:Second detectors for Compton Cameras will need to accommodate countrates on the order of 2-4 Mcps for good performance. A new high countrate Anger Camera design for electronically collimated SPECT is being developed to recover position and energy information from a scintillation waveform typically resulting from the high likelihood for pileup at these countrates. Signal outputs from each PMT of the scintillation Camera are digitized continually at 100 MHz into a ring buffer. When a Compton coincidence occurs, a snapshot of the digitized data is retrieved by a host computer for processing where correlations among the neighborhood PMT outputs are used to recover scintillation events from pileups and where position and energy information are subsequently computed. A new digital event detection algorithm is applied by using moving average filters and differentiator. The event signals generated from the new event counting algorithm are utilized to detect the starting time of each piled up event. Subsequent to detection and time estimation, a maximum likelihood position and energy estimation algorithm has been developed to deal with the highly piled up events
A. Longoni - One of the best experts on this subject based on the ideXlab platform.
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First results of the HICAM Anger Camera
2009 IEEE Nuclear Science Symposium Conference Record (NSS MIC), 2009Co-Authors: Carlo Fiorini, A. Longoni, P. Busca, Alberto Gola, R. Peloso, Andrea Abba, A. Geraci, G. Padovini, Heike Soltau, Brian HuttonAbstract:We are developing a new Anger Camera for nuclear imaging in the framework of the HICAM (HIgh resolution Camera) project supported by European Community. The Camera is foreseen to be employed in applications where high-position resolution (~ 1 mm intrinsic spatial resolution) and Camera compactness are of primary concern. The Camera is based on the use of monolithic arrays of Silicon Drift Detectors (SDDs), each one with a JFET integrated in the detector chip. In this work we present the results of the characterization of a first prototype of the Camera (1/4 of the final expected active area), composed by 25 SDDs of 1cm2 each in a 5×5 format. The module is read-out by a single 25-channels ASIC. The prototype of the Camera is presented in this work together with the results of the gamma-ray imaging characterization.
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HICAM: Development of a high-resolution Anger Camera for nuclear medicine
2008 IEEE Nuclear Science Symposium Conference Record, 2008Co-Authors: Carlo Fiorini, A. Longoni, Alberto Gola, R. Peloso, A. Geraci, G. Padovini, Brian Hutton, Peter Lechner, L. Struder, Kjell ErlandssonAbstract:A new Anger Camera for nuclear imaging is under development in the framework of the HICAM (HIgh resolution Camera) project supported by European Community. It is foreseen to be employed in applications where high-position resolution and Camera compactness are of primary concern. Thanks to a higher intrinsic resolution (≪1mm), an advanced collimator technology and the Camera compactness, it would be possible to achieve an overall improvement of imaging performance of ∼ 2.5 mm (at an imaging distance of 5 cm). The Silicon Drift Detectors (SDDs) used in this Camera have recently shown to be a competitive device for the readout of scintillator with respect to conventional photodetectors like photomultiplier tubes, thanks to their high quantum efficiency and low electronics noise. HICAM Camera will be composed by 100 SDDs of 1cm2 each in a 10 cm × 10 cm format. The modular structure of this Camera, as well as the preliminary results of the development of its sub-systems, is presented in this work.
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Present and future Anger Cameras based on Silicon Drift Detectors
2007 IEEE Nuclear Science Symposium Conference Record, 2007Co-Authors: Carlo Fiorini, A. Longoni, Alberto Gola, R. Peloso, Peter Lechner, L. Struder, Alan OwensAbstract:Silicon drift detectors (SDDs) have recently shown to be a competitive device for the readout of scintillator with respect to conventional photodetectors like photomultiplier tubes, thanks to their high quantum efficiency and low electronics noise. In particular, arrays of SDDs could represent an interesting photodetector to be employed in the development of Anger Cameras with high position resolution. Recently, we have developed the DRAGO Camera, which is a high-resolution Anger Camera based on a monolithic array of 77 SDDs, with an active area of 6.7 cm2, coupled to a scintillator crystal. The performances achieved in gamma-ray imaging using this Camera are first reported in this work. According to the achieved results, we are now designing a new Anger Camera, in the framework of the HICAM project, composed by 100 SDDs of 1 cm2 each in a 10times10 cm2 format. This Camera is foreseen to be employed in application mainly for human imaging where high-position resolution and Camera compactness are of primary interest. The main issues of the design of this Camera as well as the results of Montecarlo simulations of its performances are presented in this work. As a basic unit for this Camera, we have experimentally characterized the electronics noise and gamma-ray performances, when coupled to a scintillator, of a SDD of 1 cm2 of active area. This device shows excellent performances in terms of electronics noise with moderate cooling achieved by a Peltier element.
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A small prototype of LSO-SDD Anger Camera
IEEE Transactions on Nuclear Science, 2004Co-Authors: Carlo Fiorini, F. Perotti, E. Rossi, A. Longoni, C. LabantiAbstract:In this paper, we present a small prototype of Anger Camera based on a monolithic array of silicon drift detectors (SDDs) coupled to a single LSO scintillator. The SDD photodetector consists of an array of 19 hexagonal units with on-chip JFET and has about 1 cm/sup 2/ of total sensitive area. The SDD array was already successfully tested with a CsI(Tl) crystal. However, the long scintillation decay time of CsI(Tl) requires the use of a long shaping time to reduce the effect of the ballistic deficit. This requirement does not allow to fully exploit the low electronics noise of the SDD, which, on the contrary, reaches its minimum noise at short shaping times. Moreover, the use of a faster scintillator would improve the overall counting rate capability of the Anger Camera. On the other side, the LSO scintillator is characterized by a lower scintillation conversion efficiency with respect to CsI(Tl) and by a natural background. In this work the performances which could be expected from a LSO-SDD Anger Camera are first evaluated. Then, the results achieved in the experimental characterization of a prototype of this detector are presented. A position resolution better than 1 mm FWHM using a /sup 57/Co source (122 keV) has been measured.
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Experimental characterization of a small prototype of LSO-SDD Anger Camera
2003 IEEE Nuclear Science Symposium. Conference Record (IEEE Cat. No.03CH37515), 2003Co-Authors: Carlo Fiorini, F. Perotti, A. Longoni, C. Labanti, E. RossiAbstract:In this work we present a small prototype of Anger Camera based on a monolithic array of Silicon Drift Detectors (SDDs) coupled to a single LSO scintillator. The SDD photodetector consists of an array of 19 hexagonal units with onchip JFET and has about 1 cm/sup 2/ of total sensitive area. The SDD array was already successfully tested with a CsI(Tl) crystal. However, the long scintillation decay time of CsI(Tl) requires the use of a long shaping time to reduce the effect of the ballistic deficit. This requirement does not allow to fully exploit the low electronics noise of the SDD, which, on the contrary, reaches its minimum at short shaping times. Moreover, the use of a faster scintillator would improve the overall counting rate capability of the Anger Camera. On the other side, the LSO scintillator is characterized by a lower scintillation conversion efficiency with respect to CsI(Tl) and by a natural background. In this work the performances which could be expected from a LSO-SDD Anger Camera are first evaluated. Then, the results achieved in the experimental characterization of a prototype of this detector are presented. A position resolution better than 1 mm FWHM using a /sup 57/Co source (122 keV) has been measured.
