NUCMED 1

• Nuclear medicine also known functional studies and physiologic imaging modality
• Nuclear medicine is a medical specialty that focuses on the use of radioactive materials called radiopharmaceuticals for diagnosis, therapy and medical research
• Radiopharmaceuticals is a radioactive drugs used in the diagnosis and treatment of disease
• Radiopharmaceuticals is a combination of radioactive molecule and biologically active molecule
• Radioactive molecule emits radiation
• Biologically active molecule guides radioactive molecule going to the specific cell body location or tissues
• Atom is a building block or smallest particle
• Atom 2 basic parts are nucleus and orbital elements
• 3 principal types of subatomic particles that compose an Atom are: Electron, Proton and Neutron
• Element is the simplest form of matter (carbon, hydrogen, oxygen, nitrogen, etc.)
• Molecule two or more atoms chemically combined (water, nitrogen, ozone, calcium oxide)
• compound is a chemical combination of 2 or more different types of atom (sucrose, sodium chloride, water, carbon dioxide)
• The nucleus consists of protons and neutrons which are made of quarks bound together by gluons
• protons "up" quarlk +2/3 e
• neutron "down" quarks -1/3e
• Electron is the lightest, smallest subatomic particles and are found in the extra nuclear proton of the atom
• Electron is also called negatrons and are given symbol of e or e-, it carries negative charge
• Electron has a small mass of 9.1 x 10^-31 kg or 0.00055amu. Discovered by J.J Thompson in 1897
• Proton found within the nucleus of an atom and are symbolyzed by p or p+.
• Proton carries positive charge to the nucleus
• Proton has a relative mass of 1836, and a mass of 1.673x10^-27 or 1.00728 amu
• Proton was discovered by E. Goldstein in 1886
• Neutron is the heaviest and has particles within the nucleus of an atom. N^0, it is neutral. No electrical charge
• Neutron has a relative mass of 1838 and a mass of 1.675x10^-27 kg or 1.00867 amu. Discovered by J. Chadwick in 1932
• Radiation is the transfer of energy through space
• Exposed/Irradiated - matter that intercepts and absorbs radiation
• Ionization is the removal of electron from the atom. It occurs when incident energy is greater than electron binding energy
• Excitation is the addition to a system achieved by raising the energy binding energy
• Excitation occurs when incident xrays energy less than electron binding energy
• Ionizing Radiation any type of radiation capable of removing an orbital electron from the atom with which it interacts. It results in Ion pair and Characteristics x-rays
• Examples of Ionizing Radiation: X-rays, gamma rays, uv light
• Types of Ionizing Radiation: Particulate and Electromagnetic
• Particulate - no mass and charge. Alpha and Beta
• Electromagnetic - no mass and no charge (photons) travels in the speed of light. Gamma and xrays
• Low-energy xray - it interacts with whole atom
• Moderate-energy x-ray interacts with electrons
• High-energy xray it interacts with nucleus
• Coherent - photon vs electrons (no ionization)
• Compton - photon vs electron (outermost shell)
• Photoelectric - photon vs electron (innermost shell)