Radionuclide Production - Nuclear Medicine
- 1. Radionuclide Production Summed Information For The Most used Radionuclide in NM Department Done by: Budour Alzahrani Nuclear Medicine Specialist, PSMMC, Riyadh All copyrights for Saudi Nuclear Medicine Club
- 2. Contents • Radionuclide Production • Reactors • Cyclotrons • Generators • Tc99m Generator • Rb Generator • Kr81 Generator • References www.snmclub.com
- 3. Type of Radionuclide Production Generators Cyclotrons Reactors www.snmclub.com
- 5. Reactors • It is composed of fuel rods. • Contain large unstable atoms of uranium- 235, uranium-238, or plutonium- 239. • The fission process is a source of a number of widely used radioisotopes (90Sr, 99Mo, 131I and 133Xe). www.snmclub.com
- 6. Fission • Fission is simply splitting the nuclei into two parts; those two parts become new smaller nuclides. • The fission fragments move apart rapidly due to high kinetic energy and simultaneously give off gamma emissions and two to five neutrons. • The majority of fission fragments will have an unequal mass number, called : fission pairs. • Iodine-131 (131I) and cesium-137 (137Cs) are fission pairs . • The neutrons produced is ‘fast’ and energetic but can be slowed down (thermalized or moderated) using scatter reactions. Water and heavy water (2H2O) used as moderators in a nuclear reactors. www.snmclub.com
- 8. Cyclotrons • The cyclotron bombards a stable nuclei with high energy charged particles, like protons (p), and alpha (α) particles. • To penetrate the nucleus of the target, the particles must be accelerated to very high energies in a spiral path within a vacuum. www.snmclub.com
- 10. Generators • Radionuclide generator contain a parent/daughter radionuclide. • The Parent is longer half life than the daughter. • Extraction of the daughter from the parent, called : elution. • Elution is also referred to ‘milking’. www.snmclub.com
- 11. Common used Generators in NM department www.snmclub.com
- 12. 99mTC Generator • 99Mo / 99mTc generator is the most common. • 99Mo has a 67 hour half-life • 99Mo is produced by fission and loaded onto an aluminum column by adsorption in the generator as ammonium molybdenate . • 99mTc has different chemical properties to the parent, it’s less tightly bound to the aluminum column • Normal saline across the aluminum column to remove the 99mTc from the column to produce eluate . • Technetium activity can be builds up again, maximum activity available in the next 24 hours. www.snmclub.com
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- 14. 81Rb / 81Kr Generator • Radionuclide generator. The parent (Rubidium-81) is fixied on a membrane, which the daughter (krypton-81m) is eluted by the passing of air. • 81Rb nuclide is produced on U-120M cyclotron via Kr(p, 2n)Rb reaction using pressurized gaseous target. • Used for lung ventilation studies. • The parent Rb81 has a half-life of 4.58 hours, decaying to Kr81m which has a half-life of 13 sec. • Higher gamma energy than 99mTc. www.snmclub.com