Evaluation of Crystals’ Morphology on Detection Efficiency Using Modern Classification Criterion and Monte Carlo Method in Nuclear Medicine
- 13 Downloads
Crystals used in medical imaging systems play a key role in obtaining images for the improvement of diagnoses in medicine. We investigated crystal material characteristics in detection efficiency, and a reliable definition of efficiency proposed for improving spatial resolution. In this study, bismuth germanate (BGO), lutetium oxyortho silicate, gadolinium silicate, and lutetium yttrium oxyortho silicate crystals have been evaluated to compare their special characteristics using Monte Carlo simulation. Additionally, a new criterion is introduced as scattering frequency at which the ratio of the number of Compton interaction to the minimum traversed distance of photons in crystal is suggested. This frequency is based on random numbers, Compton scattering, energy of γ-ray, geometry and material of crystal. The sensitivity of crystals as a function of crystal width at various incident angles of the photon is investigated. The simulated results have demonstrated that at a distinct width of crystal, the detection efficiency of the BGO crystal was more than that of other crystals in which the amount of scatter and random coincidences decreased. Crystal width at various applications, however, must be optimized with respect to the trade off among the signal-to-noise ratio, spatial and temporal resolutions, efficiency, and the untrue coincidences. Determining crystal width and material may be useful in collimator design to improve spatial resolution and efficiency.
KeywordsMaterials modelling Crystal Compton scattering Detection efficiency Nuclear physics Monte Carlo simulation
Authors thank Ms. Sahar Ghavidel, Queen’s University for comments that greatly improved the manuscript. They are also immensely grateful to Ahmad Ansari for his financial support in foundation of Gerash University and Hospital as well as their equipments.
Compliance with Ethical Standards
Conflict of interest
The authors have declared no conflicts of interest.
- 6.Tzanakos G, Monoyiou E, Alexandratou E (1998) A Monte Carlo study of LSO γ-ray detectors for PET. In: SPIE’s international symposium ‘Medical Imaging 1998’, San Diego, CA, 21–27 Feb 1998Google Scholar
- 10.Michel C, Eriksson L, Rothfuss H, Bendriem B (2006) Influence of crystal material on the performance of the HiRez 3D PET scanner: a Monte-Carlo study. IEEE Nucl Sci Symp Conf Rec 4:2528–2531Google Scholar
- 11.Brasse D, Piqueras I, Guyonnet J-L (2004) Design of a small animal PET system with high detection efficiency. IEEE Nucl Sci Symp Conf Rec 4:2412–2416Google Scholar
- 16.Vandenbroucke A, Foudray AMK, Olcott PD, Levin CS (2011) Performance characterization of a new high resolution PET scintillation detector. Phys Med Biol 56(3):4135–4145Google Scholar
- 17.Knoll GF (2010) Radiation detection and measurement, chap 2, 4th edn. Wiley, New YorkGoogle Scholar
- 23.Nikolopoulos D, Kandarakis I, Tsantilas X, Valais I, Cavouras D, Louizi A (2006) Comparative study using Monte Carlo methods of the radiation detection efficiency of LSO, LuAP, GSO and YAP scintillators for use in positron emission imaging (PET). Nucl Instrum Methods Phys Res A 569:350–354ADSCrossRefGoogle Scholar
- 24.Khorshidi A (2017) Accelerator driven neutron source design via beryllium target and 208Pb moderator for boron neutron capture therapy in alternative treatment strategy by Monte Carlo method. J Cancer Res Ther 13:456–465Google Scholar