| Автор | Frans van der Have |
| Автор | Freek J Beekman |
| Дата выпуска | 2004-04-21 |
| dc.description | Pinhole SPECT is rapidly gaining popularity for imaging laboratory animals using gamma-emitting molecules. Penetration and scattering of gamma radiation in the pinhole edge material can account for a significant fraction of the total number of photons detected, particularly if the pinholes have small diameters. This study characterizes the effects of penetration and scatter with micro-pinholes made of lead, tungsten, gold and platinum. Monte Carlo simulations are performed for I-125 (27–35 keV) and Tc-99m (140 keV) point sources with pinhole diameters ranging from 50 to 500 µm. The simulations account for the effects of photo-electric interaction, Rayleigh scattering, Compton scattering, ionization, bremsstrahlung and electron multiple scattering. As a typical example, in the case of a Tc-99m point source and pinholes with a diameter of 300 µm in gold or platinum, approximately 55% of the photons detected resulted from penetration and approximately 3% from scatter. For pinhole diameters ranging from 100 to 500 µm, the penetration fraction for tungsten and lead was approx a factor of 1.0 to 1.6 higher and the scatter fraction was 1.0 to 1.8 times higher than in case of gold or platinum. Using I-125 instead of Tc-99m decreases the penetration fraction by a factor ranging from 3 to 11 and the scatter fraction by a factor ranging from 12 to 40. For all materials studied, the total amounts of penetrated and scattered photons changed approximately linearly with respect to the pinhole diameter. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Копирайт | 2004 IOP Publishing Ltd |
| Название | Photon penetration and scatter in micro-pinhole imaging: a Monte Carlo investigation |
| Тип | paper |
| DOI | 10.1088/0031-9155/49/8/001 |
| Electronic ISSN | 1361-6560 |
| Print ISSN | 0031-9155 |
| Журнал | Physics in Medicine and Biology |
| Том | 49 |
| Первая страница | 1369 |
| Последняя страница | 1386 |
| Аффилиация | Frans van der Have; Image Sciences Institute and Rudolf Magnus Institute of Neuroscience, UMC Utrecht STR 5.203, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands |
| Аффилиация | Freek J Beekman; Image Sciences Institute and Rudolf Magnus Institute of Neuroscience, UMC Utrecht STR 5.203, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands |
| Выпуск | 8 |
