Prelim Topic 1 Flashcards
It is a branch of medicine that deals with the use of radioactive substance in diagnosis or treatment of diseases.
Nuclear medicine (nucmed)
The history of nuclear medicine is rich with contributions from gifted scientists across different disciplines in
Physics, chemistry, engineering and medicine
often called the “father of nuclear medicine,” developed the tracer principle. He coined the term radioindicator and extended his studies from inorganic to organic chemistry.
1923, georg de hevesy
discovery of artificial radioactivity in?
1934
production of radionuclides by __ for medicine related use in.
1946, Oak Ridge National Laboratory
Cyclotron was invented by?
Ernest Lawrence in 1931.
Many historians consider the discovery of artificially produced radioisotopes by __ and __in __ as the most significant milestone in Nuclear Medicine.
Frederic Joliot and Irene Curie - Joliot,1934
Nuclear Reactors were developed by __ and his colleagues in .
Enrico Fermi, 1946
Physics of nucmed
Atomic structure, radioactivity, decay processes
Came from the Greek word, “atomos” which means indivisible Smallest part of an element that has all the properties of that element. The basic component and the smallest unit of matter.
Atom
Basically, it is __ because the number of protons is equal to the number of electrons
neutrally charged
The atom is made of two basic parts;
the nucleus (nuclear portion) and the orbital electrons (extra nuclear portion).
Parts of an atom
Nucleus, orbits/shells
Central core of an atom, Contains nearly all the mass of an atom, Positively charged, Contains the nucleons (protons+neutrons)
Nucleus
Composed of electrons, which is negatively charged.
Orbits/shells
3 subatomic particles
Proton, neutron, electron
Found within the nucleus of an atom and are symbolized by letter p or p+. They provide positive charge to the nucleus. Total number of protons equals atomic number (Z) of an element.
Protons
Protons Has a mass of.
1.673 x 10 -27 kg or 1.00783 amu
Protons was Discovered by__ in__.
E. Goldstein, 1886
Neutral particles within the nucleus of the atom. Slightly heavier than protons. No electric charge. Symbolized by the letter n.
Neutrons
Mass of neutron
75 x 10 -27 kg or 1.0090 amu.
Neutron was Discovered by __ in __.
J. Chadwick, 1932
Smallest of the subatomic particles and are found in the extra nuclear portion of the atom.
Are called negatrons and are given the symbol е or e-.
Electrons
Electrons Has a small mass of
9.1 x 10 -31kg or 0.00055 amu.
Electrons was Discovered by__ in__.
J. J. Thompson, 1897
The nucleus is composed of two types of these particles- protons and neutrons; hence protons and neutrons are called
Nucleons
Radioactivity Discovered in __ by the French Scientist
1986, Antoine Henri Becquerel
Is the emission of particle or energy to attain stability. It decays by spitting out : Mass (alpha particle), Charge (Beta particle), Energy (Gamma Rays).
Radioactivity
Si unit of radioactivity
Becquerel (Bq)
1 Bq =?
1dis/s (disintegration per second or dps)
Old unit of radioactivity is?
Curie (Ci)
__ who coined the term radioactivity and also discovered Polonium and Radium, with the help of her husband, __
Marie curie, pierre curie
unstable of emitting radiation spontaneously to reach a more stable state; termed also as radioactive materials
Radioactive atoms
There are three reasons/conditions why substance might be radioactive Its nucleus may be unstable because it has either:
Too many protons, too many neutrons, too many neutrons and protons
A fraction or percentage of original number of atoms decaying per unit time
Decay Disintegration / Transformation Constant
The amount of time taken by the radioactive material (RAM) or radioactive atom to decay to ½ of its original value
Every RAM has its own unique half life value
Half life
Common RAM half-lives
Element - half-life
Tc-99m =
I-131 =
I-123 =
Ra-223 =
Ra-226 =
Co-60 =
Cs-137 =
Ir-192 =
Sr-90 =
Mo-99 =
6 hrs
8 days
13 hrs
11 days
1620 yrs
5.26 yrs
30 yrs
74 days
28 yrs
66 hrs
describes the rate of radioactive decay and the quantity of the material present at any given time.
Radioactive decay law
is the time required so that activity of radionuclide is reduced to 50%.
Physical Half-life
is the time required for the body to eliminate half of an administered dosage of any substance by regular process of deliberation.
Biological Half-life
is the time required for a radioactive elimination in the body to be diminished by 50% as a result of the combined action of the Radioactive Decay and Biological Elimination.
Effective Half-life
Most gamma rays are emitted almost immediately (__) after the primary
decay process, whether it be __,__, , or __
<10-12 second, alpha decay, negatron decay, positron decay, electron capture
When the intermediate excited state last longer than __ , the term “__ ” is used.
10-9 second, metastable
Atomic notation
A-
Z-
X-
Atomic mass (numbers of nucleons)
Atomic number (number of protons and electrons)
Element symbol
the process wherein the unstable atom (parent) spontaneously emits radiation to reach a more stable state (daughter)
Radioactive decay
Any atomic species characterized by the atomic mass number (A), protons (Z), and number of neutron (N).
Nuclides
the original nuclide that undergoes radioactive decay.
Parent Nuclide
the more stable nuclide which results from radioactive decay.
Daughter Nuclide
Occurs in heavy nuclides with high atomic number
It resembles the Helium (He) element
Alpha emission decay (a-decay)
The relative charge of alpha is _ and a mass of _
2, 4
has low penetrating power and most harmful internally and less harmful externally.
Alpha radiation
it can be stopped by a piece of __ or __.
Paper, cloth
The relative charge of -1 and a mass of 0.
The β-decay has a moderate energy and it can be stopped by approximately 0.5mm aluminum or lead.
Beta decay/emission
Beta decay/emission Has two sub-modes:
a. Negatron emission
b. Positron emission.
This occurs when there are too many neutrons. It occurs when a radioactive nuclide with high Neutron and Proton ratio disintegration This particle emitted is a negatively charge high speed electron which originated in the nucleus. This electrons results from the conversion of the excess neutron into proton.
Negatron emission
It occurs when the radioactive nuclide with an excess of Proton disintegrates
• The particle emitted is positively charged electron which comes from the nucleus
• This results from the transformation of the excess proton to a neutron
Positron emission or beta positive emission
Excited state element
• Radionuclide that yields another nuclide during disintegration
• Long-lived radionuclide
Parent nuclide
Ground state element
• Element that results from the radioactive decay of a parent element.
• Short-lived radionuclide
Daughter nuclide
Have high penetrating power and it can be stopped by several centimeters of lead.
Gamma rays and xrays
Gamma ray originates from the __
• X-ray originates from the __
nucleus, electrons
Beta particles originate from the __
• Electrons originate from the __
nucleus, e- clouds.
