Analytical Modeling of a Slit Collimator and Optimization for Small Animal Imaging Applications
Abstract
Introduction: The collimator design and optimization are essential in small animal molecular imaging for preclinical studies. In this study, a mathematical model was derived and used to optimize the slit collimator for small animal imaging applications.
Materials and Methods: The geometric efficiency was formulated as a source-to-detector distance for a certain amount of the collimator resolution (). The first-order derivative of the derived formula gives the optimized parameters. The detector performance was modeled in terms of intrinsic resolution . Furthermore, the edge penetration effect was considered using the validated model.
Results: Optimum source-to-detector distance was found as . For an ideal detector, optimal, geometric efficiency and slit aperture width were found as , and , respectively. Where and are the source-to-collimator distance and detector length, respectively. For the fixed resolution of 1.0 mm, the sensitivity for different source-to-collimator distances of 50.0, 100.0, and 150.0 mm was calculated as, , and , respectively. In addition, for a sub-millimeter resolution of 0.5 mm at 15.0, 30.0, and 50.0 mm, the geometric efficiency was calculated as, , , and . For a typical source-to-collimator distance (15.0 mm), the optimal geometric efficiencies are, , , , and for the resolutions of 0.25, 0.50, 1.0, 1.5, and 2.0 mm, respectively.
Conclusion: Based on the analytic model predictions, the performance characteristics of the slit collimator in terms of geometric efficiency and resolution were extracted. The importance of the proposed model lies both in its speed and ease of application.
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13- Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, and Mohammad Reza Ay, "Spinning slithole collimation for high-sensitivity small animal SPECT: Design and assessment using GATE simulation." Physica Medica, Vol. 40pp. 42-50, (2017).
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15- MCM Rentmeester, F Van Der Have, and FJ Beekman, "Optimizing multi-pinhole SPECT geometries using an analytical model." Physics in Medicine & Biology, Vol. 52 (No. 9), p. 2567, (2007).
16- Lars R Furenlid et al., "FastSPECT II: a second-generation high-resolution dynamic SPECT imager." IEEE Transactions on Nuclear Science, Vol. 51 (No. 3), pp. 631-35, (2004).
17- Freek J Beekman and Brendan Vastenhouw, "Design and simulation of a high-resolution stationary SPECT system for small animals." Physics in Medicine & Biology, Vol. 49 (No. 19), p. 4579, (2004).
18- Roberto Massari, Annunziata D’Elia, Andea Soluri, and Alessandro Soluri, "Super Spatial Resolution (SSR) method for small animal SPECT imaging: A Monte Carlo study." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 982p. 164584, (2020).
19- Johan Nuyts, Kathleen Vunckx, Michel Defrise, and Christian Vanhove, "Small animal imaging with multi-pinhole SPECT." Methods, Vol. 48 (No. 2), pp. 83-91, (2009).
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21- Gengsheng L Zeng and Daniel Gagnon, "CdZnTe strip detector SPECT imaging with a slit collimator." Physics in Medicine & Biology, Vol. 49 (No. 11), p. 2257, (2004).
22- Shelan T Mahmood, Kjell Erlandsson, Ian Cullum, and Brian Forbes Hutton, "Design of a novel slit-slat collimator system for SPECT imaging of the human brain." Physics in Medicine & Biology, Vol. 54 (No. 11), p. 3433, (2009).
23- Frans Van Der Have et al., "U-SPECT-II: an ultra-high-resolution device for molecular small-animal imaging." Journal of Nuclear Medicine, Vol. 50 (No. 4), pp. 599-605, (2009).
24- Scott D Metzler, Roberto Accorsi, John R Novak, Ahmet S Ayan, and Ronald J Jaszczak, "On-axis sensitivity and resolution of a slit-slat collimator." Journal of Nuclear Medicine, Vol. 47 (No. 11), pp. 1884-90, (2006).
25- Etesam Malekzadeh, Hossein Rajabi, Elisa Fiorina, and Faraz Kalantari, "Derivation and validation of a sensitivity formula for knife-edge slit gamma camera: A theoretical and Monte Carlo simulation study." Iranian Journal of Nuclear Medicine, Vol. 29 (No. 2), pp. 86-92, (2021).
26- Roberto Accorsi, John R Novak, Ahmet S Ayan, and Scott D Metzler, "Derivation and validation of a sensitivity formula for slit-slat collimation." IEEE transactions on medical imaging, Vol. 27 (No. 5), pp. 709-22, (2008).
27- Martin J Berger and JH Hubbell, "XCOM: Photon cross sections on a personal computer." National Bureau of Standards, Washington, DC (USA). Center for Radiation …, (1987).
28- P Cambraia Lopes et al., "Optimization of collimator designs for real-time proton range verification by measuring prompt gamma rays." in 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), (2012): IEEE, pp. 3864-70.
29- Stephen C Moore, Kypros Kouris, and Ian Cullum, "Collimator design for single photon emission tomography." European journal of nuclear medicine, Vol. 19 (No. 2), pp. 138-50, (1992).
2- George C Kagadis, George Loudos, Konstantinos Katsanos, Steve G Langer, and George C Nikiforidis, "In vivo small animal imaging: current status and future prospects." Medical physics, Vol. 37 (No. 12), pp. 6421-42, (2010).
3- Min Wu and Jian Shu, "Multimodal molecular imaging: current status and future directions." Contrast media & molecular imaging, Vol. 2018(2018).
4- Robert S Miyaoka and Adrienne L Lehnert, "Small animal PET: a review of what we have done and where we are going." Physics in Medicine & Biology, Vol. 65 (No. 24), p. 24TR04, (2020).
5- Matthew A Kupinski and Harrison H Barrett, Small-animal SPECT imaging. Springer, (2005).
6- Steven R Meikle, Peter Kench, Michael Kassiou, and Richard B Banati, "Small animal SPECT and its place in the matrix of molecular imaging technologies." Physics in Medicine & Biology, Vol. 50 (No. 22), p. R45, (2005).
7- Annunziata D’Elia et al., "Development of a high-resolution SSR-SPECT system for preclinical imaging and neuroimaging." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 1025p. 166161, (2022).
8- Yohji Matsusaka et al., "Performance Evaluation of a Preclinical SPECT Scanner with a Collimator Designed for Medium-Sized Animals." Molecular imaging, Vol. 2022(2022).
9- Karen Van Audenhaege, Roel Van Holen, Stefaan Vandenberghe, Christian Vanhove, Scott D Metzler, and Stephen C Moore, "Review of SPECT collimator selection, optimization, and fabrication for clinical and preclinical imaging." Medical physics, Vol. 42 (No. 8), pp. 4796-813, (2015).
10- GR Gindi et al., "Imaging with rotating slit apertures and rotating collimators." Medical physics, Vol. 9 (No. 3), pp. 324-39, (1982).
11- S Webb, MA Flower, and RJ Ott, "Geometric efficiency of a rotating slit-collimator for improved planar gamma-camera imaging." Physics in Medicine & Biology, Vol. 38 (No. 5), p. 627, (1993).
12- Roel Van Holen, Stefaan Vandenberghe, Steven Staelens, and Ignace Lemahieu, "Comparing planar image quality of rotating slat and parallel hole collimation: influence of system modeling." Physics in Medicine & Biology, Vol. 53 (No. 7), p. 1989, (2008).
13- Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, and Mohammad Reza Ay, "Spinning slithole collimation for high-sensitivity small animal SPECT: Design and assessment using GATE simulation." Physica Medica, Vol. 40pp. 42-50, (2017).
14- D Uzun Ozsahin, Lisa Bläckberg, G El Fakhri, and H Sabet, "GATE simulation of a new design of pinhole SPECT system for small animal brain imaging." Journal of Instrumentation, Vol. 12 (No. 01), p. C01085, (2017).
15- MCM Rentmeester, F Van Der Have, and FJ Beekman, "Optimizing multi-pinhole SPECT geometries using an analytical model." Physics in Medicine & Biology, Vol. 52 (No. 9), p. 2567, (2007).
16- Lars R Furenlid et al., "FastSPECT II: a second-generation high-resolution dynamic SPECT imager." IEEE Transactions on Nuclear Science, Vol. 51 (No. 3), pp. 631-35, (2004).
17- Freek J Beekman and Brendan Vastenhouw, "Design and simulation of a high-resolution stationary SPECT system for small animals." Physics in Medicine & Biology, Vol. 49 (No. 19), p. 4579, (2004).
18- Roberto Massari, Annunziata D’Elia, Andea Soluri, and Alessandro Soluri, "Super Spatial Resolution (SSR) method for small animal SPECT imaging: A Monte Carlo study." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 982p. 164584, (2020).
19- Johan Nuyts, Kathleen Vunckx, Michel Defrise, and Christian Vanhove, "Small animal imaging with multi-pinhole SPECT." Methods, Vol. 48 (No. 2), pp. 83-91, (2009).
20- Minh Phuong Nguyen, Marlies C Goorden, and Freek J Beekman, "EXIRAD-HE: multi-pinhole high-resolution ex vivo imaging of high-energy isotopes." Physics in Medicine & Biology, Vol. 65 (No. 22), p. 225029, (2020).
21- Gengsheng L Zeng and Daniel Gagnon, "CdZnTe strip detector SPECT imaging with a slit collimator." Physics in Medicine & Biology, Vol. 49 (No. 11), p. 2257, (2004).
22- Shelan T Mahmood, Kjell Erlandsson, Ian Cullum, and Brian Forbes Hutton, "Design of a novel slit-slat collimator system for SPECT imaging of the human brain." Physics in Medicine & Biology, Vol. 54 (No. 11), p. 3433, (2009).
23- Frans Van Der Have et al., "U-SPECT-II: an ultra-high-resolution device for molecular small-animal imaging." Journal of Nuclear Medicine, Vol. 50 (No. 4), pp. 599-605, (2009).
24- Scott D Metzler, Roberto Accorsi, John R Novak, Ahmet S Ayan, and Ronald J Jaszczak, "On-axis sensitivity and resolution of a slit-slat collimator." Journal of Nuclear Medicine, Vol. 47 (No. 11), pp. 1884-90, (2006).
25- Etesam Malekzadeh, Hossein Rajabi, Elisa Fiorina, and Faraz Kalantari, "Derivation and validation of a sensitivity formula for knife-edge slit gamma camera: A theoretical and Monte Carlo simulation study." Iranian Journal of Nuclear Medicine, Vol. 29 (No. 2), pp. 86-92, (2021).
26- Roberto Accorsi, John R Novak, Ahmet S Ayan, and Scott D Metzler, "Derivation and validation of a sensitivity formula for slit-slat collimation." IEEE transactions on medical imaging, Vol. 27 (No. 5), pp. 709-22, (2008).
27- Martin J Berger and JH Hubbell, "XCOM: Photon cross sections on a personal computer." National Bureau of Standards, Washington, DC (USA). Center for Radiation …, (1987).
28- P Cambraia Lopes et al., "Optimization of collimator designs for real-time proton range verification by measuring prompt gamma rays." in 2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), (2012): IEEE, pp. 3864-70.
29- Stephen C Moore, Kypros Kouris, and Ian Cullum, "Collimator design for single photon emission tomography." European journal of nuclear medicine, Vol. 19 (No. 2), pp. 138-50, (1992).
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| Issue | Vol 11 No 1 (2024) | |
| Section | Technical Note | |
| DOI | https://doi.org/10.18502/fbt.v11i1.14521 | |
| Keywords | ||
| Mathematical Modelling Collimator Optimization Preclinical Imaging Single Photon Emission Computed Tomography | ||
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How to Cite
1.
Malekzadeh E. Analytical Modeling of a Slit Collimator and Optimization for Small Animal Imaging Applications. Frontiers Biomed Technol. 2023;11(1):149-157.
