| 000 | 02769cam a2200337 a 4500 | ||
|---|---|---|---|
| 003 | EG-GiCUC | ||
| 005 | 20250223031908.0 | ||
| 008 | 180101s2017 ua ho f m 000 0 eng d | ||
| 040 |
_aEG-GiCUC _beng _cEG-GiCUC |
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| 041 | 0 | _aeng | |
| 049 | _aDeposite | ||
| 097 | _aPh.D | ||
| 099 | _aCai01.12.04.Ph.D.2017.Mo.S | ||
| 100 | 0 | _aMohamed Abdelnaby Abdelazeem Ghoneim | |
| 245 | 1 | 0 |
_aScattered radiation effects on the performance of diagnostic nuclear medicine devices / _cMohamed Abdelnaby Abdelazeem Ghoneim ; Supervised Wael M. Elshemey , Mahmoud H. Khedr |
| 246 | 1 | 5 | _aتأثير الإشعاع المشتت على آداء أجهزة الطب النووى التشخيصية |
| 260 |
_aCairo : _bMohamed Abdelnaby Abdelazeem Ghoneim , _c2017 |
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| 300 |
_a106 P. : _bfacsimiles , photographs ; _c25cm |
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| 502 | _aThesis (Ph.D.) - Cairo University - Faculty of Science - Department of Biophysics | ||
| 520 | _aThis work employs a point source to investigate the effects of phantom thickness and source-to-detector distance on the extrinsic sensitivity and counting efficiency of a gamma camera with a rectangular detector. Measurements are performed using 99mTc source (0.197±3.7{u00D7}10-4 GBq) and a water phantom container (as a scattering medium). The scatter fraction is determined through the analysis of the energy spectra of 99mTc for a certain energy window. Results show the direct dependence of the calculated extrinsic counting efficiency on the solid angle subtended by a point source on a rectangular detector. The increase in water thickness from 0.0 to 200 mm resulted in an increase in the scatter fraction from 0.20 to 24.12. This increase is also associated with a decrease in the extrinsic sensitivity from 121.59 to 11.15 counts/s.GBq, and a decrease in extrinsic counting efficiency from 0.039 to 0.0036%. The increase in source-to-detector distance from 0.50 to 1.10 m is accompanied by a decrease in extrinsic sensitivity from 121.59 to 115.53 counts/s.GBq and an increase in extrinsic counting efficiency from 0.039 to 0.15%. In such point source geometry, it is found that a source-to-detector distance of 0.79±0.02 m is a good compromise for an acceptable extrinsic sensitivity and a reasonable extrinsic counting efficiency. Some important differences between the present results and published measurements using a flood source are extensively discussed | ||
| 530 | _aIssued also as CD | ||
| 653 | 4 | _aExtrinsic counting efficiency | |
| 653 | 4 | _aGamma camera | |
| 653 | 4 | _aScattered fraction | |
| 700 | 0 |
_aMahmoud H. Khedr , _eSupervisor |
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| 700 | 0 |
_aWael M. Elshemey , _eSupervisor |
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| 856 | _uhttp://172.23.153.220/th.pdf | ||
| 905 |
_aNazla _eRevisor |
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| 905 |
_aSamia _eCataloger |
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| 942 |
_2ddc _cTH |
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| 999 |
_c64362 _d64362 |
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