Daniel Strul - Academia.edu (original) (raw)
Papers by Daniel Strul
European Journal of Nuclear Medicine and Molecular Imaging, 1999
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149), 2000
The optimization of spatial resolution is a critical issue for small-animal PET scanners, and is ... more The optimization of spatial resolution is a critical issue for small-animal PET scanners, and is often addressed by Monte-Carlo simulation. Analytical models, though less versatile are very fast and their simplicity allows a direct appreciation of the influence of different model parameters. The authors have developed an analytical model for multi-layer PET systems, which provides estimates of the radial and
2008 IEEE Nuclear Science Symposium Conference Record, 2008
We have designed and constructed a small animal MR-compatible PET system for fully simultaneous M... more We have designed and constructed a small animal MR-compatible PET system for fully simultaneous MR/PET acquisitions. The scanner uses long optical fibres to distance the field sensitive PET PMTs from the high magnetic field at the centre of an MR scanner. The system has been designed to operate inside a number of different high field MRI scanners. We present a
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149), 2000
An MR-compatible PET scanner capable of acquiring PET and MR images simultaneously will require 5... more An MR-compatible PET scanner capable of acquiring PET and MR images simultaneously will require 511 keV gamma shielding to suppress the influence of activity outside the PET field of view. Suitable materials must have a magnetic permeability close to that of water and air, high density, high Z and ideally a low conductivity. Eleven materials were selected on the basis
2002 IEEE Nuclear Science Symposium Conference Record, 2003
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
IEEE Transactions on Nuclear Science, 2003
IEEE Transactions on Nuclear Science, 2000
IEEE Transactions on Nuclear Science, 2000
IEEE Transactions on Nuclear Science, 2003
1998 IEEE Nuclear Science Symposium Conference Record. 1998 IEEE Nuclear Science Symposium and Medical Imaging Conference (Cat. No.98CH36255), 1998
Physics in Medicine and Biology
Monte Carlo simulation is an essential tool in emission tomography that can assist in the design ... more Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort...
2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310), 2002
Optimising the collection of scintillation light is essential for good PET scanner performance, a... more Optimising the collection of scintillation light is essential for good PET scanner performance, and even more so when the crystals are read out through optical fibres. Acid etching had been proposed as a cost-effective alternative to mechanical polishing, but there are discrepancies between the results published so far. The aim of this work is to gain a better understanding of
The British journal of radiology, 2002
There is currently great interest in combining data from different imaging modalities, either by ... more There is currently great interest in combining data from different imaging modalities, either by image registration methods that are performed after the data has been acquired or using new devices that can acquire data from two modalities simultaneously, or near simultaneously. In this paper a small prototype NMR-compatible PET scanner capable of acquiring PET images simultaneously with either NMR images or NMR spectra is described. In an associated paper [1], Pamela Garlick describes some investigations of cardiac metabolism that have been made using this system. One of the main challenges in constructing an NMR-compatible PET scanner is that photomultiplier tubes, which are an essential element of nearly all current PET systems, will not function in a high magnetic field. In collaboration with Simon Cherry and the Crump Institute of Biomedical Imaging at UCLA Medical School, a small (5.4 cm diameter) NMR-compatible PET scanner that will operate within the bore of an NMR magnet has...
Physics in Medicine and Biology, 2003
Physics in Medicine and Biology, 2003
The optimization of spatial resolution is a critical consideration in the design of small-diamete... more The optimization of spatial resolution is a critical consideration in the design of small-diameter positron emission tomography (PET) scanners for animal imaging, and is often addressed with Monte Carlo simulations. As a faster and simpler solution, we have developed a new analytical model of the PET detector response function, and implemented the model for a small single-slice, multilayer PET scanner. The accuracy of the model has been assessed by comparison with both Monte Carlo simulations and experimental measurements published in the literature. Results from the analytical model agreed well with the Monte Carlo method, being noise free and two to three orders of magnitude faster. The only major discrepancy was a slight underestimation of the width of the point spread function by the analytical method as inter-crystal scatter is neglected. We observed good agreement between the predictions of the model and experimental measurements. For two large-diameter scanners additional discrepancies were seen due to photon acollinearity, which is not considered in the model. We have shown that the simple and fast analytical detector response function model can provide accurate estimates of spatial resolution for small-diameter PET scanners, and could be a useful tool for several applications, complementing or cross-validating other simulation methods.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
The ClearPET project of the Crystal Clear Collaboration (CCC) is building spin-off technology for... more The ClearPET project of the Crystal Clear Collaboration (CCC) is building spin-off technology for high resolution small animal Positron Emission Tomography (PET). Monte Carlo simulation is essential for optimizing the specifications of these systems with regards to their most important characteristics, such as spatial resolution, sensitivity, or count rate performance. GATE, the Geant4 Application for Tomographic Emission simulates the passing
Journal of Cerebral Blood Flow & Metabolism, 1999
Several algorithms have been proposed to improve positron emission tomography quantification by c... more Several algorithms have been proposed to improve positron emission tomography quantification by combining anatomical and functional information in a pixel-by-pixel correction scheme. The precision of these methods when applied to real data depends on the precision of the manifold correction steps, such as full-width half-maximum modeling, magnetic resonance imaging-positron emission tomography registration, tissue segmentation, or background activity estimation. A good understanding of the influence of these parameters thus is critical to the effective use of the algorithms. In the current article, the authors present a monodimensional model that allows a simple theoretical and experimental evaluation of correction imprecision. The authors then assess correction robustness in three dimensions with computer simulations, and evaluate the validity of regional SD as a correction performance criterion.
European Journal of Nuclear Medicine and Molecular Imaging, 1999
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149), 2000
The optimization of spatial resolution is a critical issue for small-animal PET scanners, and is ... more The optimization of spatial resolution is a critical issue for small-animal PET scanners, and is often addressed by Monte-Carlo simulation. Analytical models, though less versatile are very fast and their simplicity allows a direct appreciation of the influence of different model parameters. The authors have developed an analytical model for multi-layer PET systems, which provides estimates of the radial and
2008 IEEE Nuclear Science Symposium Conference Record, 2008
We have designed and constructed a small animal MR-compatible PET system for fully simultaneous M... more We have designed and constructed a small animal MR-compatible PET system for fully simultaneous MR/PET acquisitions. The scanner uses long optical fibres to distance the field sensitive PET PMTs from the high magnetic field at the centre of an MR scanner. The system has been designed to operate inside a number of different high field MRI scanners. We present a
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149), 2000
An MR-compatible PET scanner capable of acquiring PET and MR images simultaneously will require 5... more An MR-compatible PET scanner capable of acquiring PET and MR images simultaneously will require 511 keV gamma shielding to suppress the influence of activity outside the PET field of view. Suitable materials must have a magnetic permeability close to that of water and air, high density, high Z and ideally a low conductivity. Eleven materials were selected on the basis
2002 IEEE Nuclear Science Symposium Conference Record, 2003
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
IEEE Transactions on Nuclear Science, 2003
IEEE Transactions on Nuclear Science, 2000
IEEE Transactions on Nuclear Science, 2000
IEEE Transactions on Nuclear Science, 2003
1998 IEEE Nuclear Science Symposium Conference Record. 1998 IEEE Nuclear Science Symposium and Medical Imaging Conference (Cat. No.98CH36255), 1998
Physics in Medicine and Biology
Monte Carlo simulation is an essential tool in emission tomography that can assist in the design ... more Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort...
2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310), 2002
Optimising the collection of scintillation light is essential for good PET scanner performance, a... more Optimising the collection of scintillation light is essential for good PET scanner performance, and even more so when the crystals are read out through optical fibres. Acid etching had been proposed as a cost-effective alternative to mechanical polishing, but there are discrepancies between the results published so far. The aim of this work is to gain a better understanding of
The British journal of radiology, 2002
There is currently great interest in combining data from different imaging modalities, either by ... more There is currently great interest in combining data from different imaging modalities, either by image registration methods that are performed after the data has been acquired or using new devices that can acquire data from two modalities simultaneously, or near simultaneously. In this paper a small prototype NMR-compatible PET scanner capable of acquiring PET images simultaneously with either NMR images or NMR spectra is described. In an associated paper [1], Pamela Garlick describes some investigations of cardiac metabolism that have been made using this system. One of the main challenges in constructing an NMR-compatible PET scanner is that photomultiplier tubes, which are an essential element of nearly all current PET systems, will not function in a high magnetic field. In collaboration with Simon Cherry and the Crump Institute of Biomedical Imaging at UCLA Medical School, a small (5.4 cm diameter) NMR-compatible PET scanner that will operate within the bore of an NMR magnet has...
Physics in Medicine and Biology, 2003
Physics in Medicine and Biology, 2003
The optimization of spatial resolution is a critical consideration in the design of small-diamete... more The optimization of spatial resolution is a critical consideration in the design of small-diameter positron emission tomography (PET) scanners for animal imaging, and is often addressed with Monte Carlo simulations. As a faster and simpler solution, we have developed a new analytical model of the PET detector response function, and implemented the model for a small single-slice, multilayer PET scanner. The accuracy of the model has been assessed by comparison with both Monte Carlo simulations and experimental measurements published in the literature. Results from the analytical model agreed well with the Monte Carlo method, being noise free and two to three orders of magnitude faster. The only major discrepancy was a slight underestimation of the width of the point spread function by the analytical method as inter-crystal scatter is neglected. We observed good agreement between the predictions of the model and experimental measurements. For two large-diameter scanners additional discrepancies were seen due to photon acollinearity, which is not considered in the model. We have shown that the simple and fast analytical detector response function model can provide accurate estimates of spatial resolution for small-diameter PET scanners, and could be a useful tool for several applications, complementing or cross-validating other simulation methods.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
The ClearPET project of the Crystal Clear Collaboration (CCC) is building spin-off technology for... more The ClearPET project of the Crystal Clear Collaboration (CCC) is building spin-off technology for high resolution small animal Positron Emission Tomography (PET). Monte Carlo simulation is essential for optimizing the specifications of these systems with regards to their most important characteristics, such as spatial resolution, sensitivity, or count rate performance. GATE, the Geant4 Application for Tomographic Emission simulates the passing
Journal of Cerebral Blood Flow & Metabolism, 1999
Several algorithms have been proposed to improve positron emission tomography quantification by c... more Several algorithms have been proposed to improve positron emission tomography quantification by combining anatomical and functional information in a pixel-by-pixel correction scheme. The precision of these methods when applied to real data depends on the precision of the manifold correction steps, such as full-width half-maximum modeling, magnetic resonance imaging-positron emission tomography registration, tissue segmentation, or background activity estimation. A good understanding of the influence of these parameters thus is critical to the effective use of the algorithms. In the current article, the authors present a monodimensional model that allows a simple theoretical and experimental evaluation of correction imprecision. The authors then assess correction robustness in three dimensions with computer simulations, and evaluate the validity of regional SD as a correction performance criterion.