Developments in Nuclear Medicine

The number of luminescence molecules that get excited and the amount of energy absorbed from incident radiation

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Luminescence attributed to fluorescence which determines the intensity of the color observed. The principles of fluorescence require the fluorescent molecules of the fluorophore be excited from ground state by exposure to photons of light [2]. As the molecules return from excited from an excited state to ground state or any other lower energy level they dissipate the absorbed energy in various forms; heat and light (luminescence observed) being the major forms. When the fluorophore is exposed to incident radiation for a long period of time, its molecules gets more excited increasing the activity of the molecule [3]. This is because they get more time to absorb more radiation. Considering that the energy absorbed by the molecules from the incident radiation determines the energy of the emitted radiation, then increasing the energy absorbed by the molecules results in an increasing in the energy of the emitted light which relates to the intensity of the observed luminescence [4]. Therefore, particles that have been exposed to IVIS spectrum for a short time produce less luminescence compared to those that have been exposed for a shorter time [5].

The intensity of luminescence observed also depends on the number of molecules exhibiting fluorescent properties. Increasing the time of exposure enables more of the fluorescent molecules of the 18F-FDG to absorb photons energy from the incident radiation. As a result, more molecules are excited and as they return to a lower energy level most of them release the absorbed energy in the form of luminescence; hence increased the intensity of luminescence. Low time of exposure results in fewer fluorescent molecules getting excited hence lower intensity of luminescence emitted [6,7].

Tonic water and tap water fluoresce with bright blue lamination due to the presence of quinine (a fluorophore) in tonic water. Quinine absorbs light and gets excited. It then releases blue light as it returns to the less excited state [8]. Dilution affects the concentration of the fluorophores [9]. At high concentrations the quinidine particles can interact resulting in overlapping of their electronic orbitals. This results in changes in their (orbitals) energetic levels seen as peak fluorescence shift. The greater the dilution, the less the fluorescent luminescence emitted. This explains why as the drops of water were added quinine was unable to absorb light and hence could not emit blue light [10, 11]. Moreover dilution does not only affect fluorescent radiation but also affects Cerenkov radiation [12]. The principle of Cerenkov luminescence is the traveling of charged particles at a speed more than that of light in a specific medium which they are moving in [13]. Dilution alters the intensity of Cerenkov luminescence in a linear manner. As dilution increases it is, Cerenkov luminescence diminishes [13].

References

Caglioti, G., Cervellati, R., & Mezzetti, L. (1959). Performance of a large area non focusing Cerenkov counter and absolute yield of Cerenkov light. Il Nuovo Cimento, 11(6), 850-860. http://dx.doi.org/10.1007/bf02732551

Barone, M. (2008). Astroparticle, particle and space physics, detectors and medical physics applications. Singapore, SG: World Scientific.

Beddar, A., Mackie, T., & Attix, F. (1992). Cerenkov light generated in optical fibres and other light pipes irradiated by electron beams. Physics In Medicine And Biology, 37(4), 925-935. http://dx.doi.org/10.1088/0031-9155/37/4/007

Blahd, W. (1971). Nuclear medicine. New York: McGraw-Hill.

Current Readings in Nuclear Medicine. (2007). Clinical Nuclear Medicine, 32(4), 344-348. http://dx.doi.org/10.1097/01.rlu.0000260096.78440.38

Fruin, J., & Jelley, J. (1968). Servo systems for Cerenkov light receivers. Can. J. Phys., 46(10), S1118-S1121. http://dx.doi.org/10.1139/p68-433

Georgescu, I. (2012). Cerenkov radiation: Light from ripples. Nat Phys, 8(10), 704-704. http://dx.doi.org/10.1038/nphys2447

Guillot, M., Gingras, L., Archambault, L., Beddar, S., & Beaulieu, L. (2011). Spectral method for the correction of the Cerenkov light effect in plastic scintillation detectors: A comparison study of calibration procedures and validation in Cerenkov light-dominated situations. Med. Phys., 38(4), 2140. http://dx.doi.org/10.1118/1.3562896

Keenan, A. (2000). Nuclear Oncology. Clinical Nuclear Medicine, 25(8), 650. http://dx.doi.org/10.1097/00003072-200008000-00026

Khan, S. (2008). Clinical Nuclear Medicine. Nuclear Medicine Communications, 29(9), 842. http://dx.doi.org/10.1097/mnm.0b013e328306c902

Kovacs, F. (1990). Themistocle: A high angular resolution Cerenkov light detector. Nuclear Physics B - Proceedings Supplements, 14(1), 330-335. http://dx.doi.org/10.1016/0920-5632(90)90440-6

Leontic, B. (1967). A corrected optical system for wide angle Cerenkov light. Nuclear Instruments And Methods, 56(1), 32-44. http://dx.doi.org/10.1016/0029-554x(67)90256-x

Leroy, C., & Rancoita, P. (2009). Principles of radiation interaction in matter and detection. Singapore: World Scientific Pub. Co.

SOLANKI, K. (1994). Developments in nuclear medicine. Nuclear Medicine Communications, 15(5), 399. http://dx.doi.org/10.1097/00006231-199405000-00012

van Albada, T., & Borgman, J. (1960). A Standard Light-Source for Photoelectric Photometry Based on Cerenkov Radiation. Apj, 132, 511. http://dx.doi.org/10.1086/146954

Winn, D., & Worstell, W. (1989). Compensating hadron calorimeters with Cerenkov light. IEEE Trans. Nucl. Sci., 36(1), 334-338. http://dx.doi.org/10.1109/23.34459

Wissel, S. (2010). Observations of direct Cerenkov light in ground-based telescopes and the flux of iron nuclei at TeV energies.

Leslie, W., & Greenberg, I. (2003). Nuclear medicine. Georgetown, Tex.: Landes Bioscience.

Ma, X., Wang, J., & Cheng, Z. (2014). Cerenkov radiation: a multi-functional approach for biological sciences. Front. Physics, 2. http://dx.doi.org/10.3389/fphy.2014.00004

Michael, B., Harrop, H., & Held, K. (1981). Photoreactivation of Escherichia Coli after Exposure to Ionizing Radiation: The Role of U.V. Damage by Concomitant Cerenkov Light. International Journal Of Radiation Biology And Related Studies In Physics, Chemistry And Medicine, 39(5), 577-583. http://dx.doi.org/10.1080/09553008114550691

Hayata, K., & Koshiba, M. (1989). Numerical simulation of guided-wave SHG light sources utilising Cerenkov radiation scheme. Electron. Lett., 25(6), 376. http://dx.doi.org/10.1049/el:19890260

Helo, Y., Kacperek, A., Rosenberg, I., Royle, G., & Gibson, A. (2014). The physics of Cerenkov light production during proton therapy. Physics In Medicine And Biology, 59(23), 7107-7123. http://dx.doi.org/10.1088/0031-9155/59/23/7107

Henkin, R. (1996). Nuclear medicine. St. Louis: Mosby.

Murphy, W., & Murphy, J. (1994). Nuclear medicine. New York: Chelsea House Publishers.

Osborn, R. (1969). Efficient light collection in gas Cerenkov counters. Nuclear Instruments And Methods, 76(1), 61-69. http://dx.doi.org/10.1016/0029-554x(69)90290-0

Redpath, J., Zabilansky, E., Morgan, T., & Ward, J. (1981). Cerenkov Light and the Production of Photoreactivatable Damage in X-irradiated E. Coli. International Journal Of Radiation Biology And Related Studies In Physics, Chemistry And Medicine, 39(5), 569-575. http://dx.doi.org/10.1080/09553008114550681