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YALPHA DECA
Release of helium ions from the nucleus of an atom
Helium ion
is-composed of two protons and two neutrons and have a 2+ charge
- A new atom is produced but has atomic number two less than the original atom and an atomic weight that is four less
- A typical alpha decay reaction Is the conversion of Uranium-238 to Thorium
Effects of the original atom during Alpha decay
Alpha emission
is accompanied quite often by gamma radiation
alpha-emitters
Many largest elements in the periodic table are
- A nucleus must be extremely unstable to emit an alpha particle
-Only heavy radioisotopes are capable of alpha emission
- Some radioisotopes are pure alpha emitters, but most emit gamma rays simultaneously with the particle emission
HOW ALPHA DECAY OCCURS
beta particle
is high energy electron that is emitted from the nucleus
proton
At the same time that the electron is being ejected from the nucleus, a neutron is becoming a ___
one; beta
BETA DECAY: Proton stays in the nucleus, increasing the atomic number of the atom by ___.
Electron is ejected from the nucleus and is the particle of radiation called ___
Thorium - 234
An example of a beta decay is
nuclear reactions
Frequently, gamma ray production accompanies ____ of all types
gamma rays
Virtually, all of the nuclear reactions also emit ___
URANIUM-p238 Decay process,
GAMMA RADIATION: two gamma rays of different energies are emitted in addition to the alpha particle
NEUTRON EMISSION
POSITRON OR BETA PLUS β+ EMISSION
ELECTRON CAPTURE
OTHER TYPES OF DECAY
NEUTRON EMISSION
An ejection of one or more neutrons from a nucleus
NEUTRON EMISSION
Occurs in nuclei that are neutron rich/proton poor
NEUTRON EMISSION
Does not transmute into a different element but becomes a different isotope of the original element
beta decay
NEUTRON EMISSION: An isolated neutron is unstable and decays by emitting an electron and becoming a proton with a half-life of 10.5 minutes. When this occurs while the neutron is part of an atom, it is called ____.
POSITRON OR BETA PLUS β+ EMISSION
Anti-matter equivalent of an electron
POSITRON OR BETA PLUS β+ EMISSION
Same mass as an electron but an opposite electrical charge
POSITRON OR BETA PLUS β+ EMISSION
Emitted from unstable isotopes that have too few neutrons to be stable
POSITRON OR BETA PLUS β+ EMISSION
A proton is transformed into a neutron
pair-production
POSITRON OR BETA PLUS β+ EMISSION :Gamma rays of more than 1 MeV interact with matter in a process called
POSITRON OR BETA PLUS β+ EMISSION
Useful in Nuclear Medicine PET (Positron Emission Tomography) procedure
ELECTRON CAPTURE
Occurs when there are too many protons in the nucleus and there is not enough energy to emit a positron
ELECTRON CAPTURE
One of the orbital electrons is captured by a proton
ELECTRON CAPTURE
One of the orbital electrons is captured by a proton. This creates a ___ and a ___ which is emitted
new element
ELECTRON CAPTURE; A change of number of protons transforms a nuclide into a
characteristic x-ray
ELECTRON CAPTURE: Additional consequence in the process: a different electron fills the void of the orbital shell of an atom and releases a
Collisional Interactions
Radiative Interactions
ELECTRON INTERACTION WITH MATTER
TWO TYPES
Collisional Interactions
Incident electron interacts with atomic electrons in the absorbing medium
SOFT COLLISIONS
HARD COLLISIONS
Collisional Interactions TYPES
SOFT COLLISIONS
Passes an atom at a considerable distance and affects the atom as a whole
SOFT COLLISIONS
Result: excite and sometimes ionize valence electrons
HARD COLLISIONS
Incident electron interacts with atomic electron
HARD COLLISIONS
Result: atomic electron ejected with considerable kinetic energy
Radiative Interactions
Incident electron interacts with atomic nuclei in the absorbing medium
ELASTIC INTERACTION
INELASTIC INTERACTION
Radiative Interactions TYPES
ELASTIC INTERACTION
Electron is scattered with NO CHANGE IN ENERGY
ELASTIC INTERACTION
Probability of occurrence INCREASES when atomic number (Z) of material increases
INELASTIC INTERACTION
Electron reacts with the nuclear field of the atom resulting to BREMSSTRAHLUNG RADIATION
INELASTIC INTERACTION
Result: energy is carried away via emission of radiation (Bremsstrahlung x-rays)
They are the primary mechanism through which radioactive isotopes (administered as radiopharmaceuticals) deposit energy within the body, allowing for diagnosis and treatment of diseases
ELECTRON INTERACTIONS
Why are they crucial in Nuclear Medicine?
diagnostic nuclear medicine
In ____, the emitted gamma rays produced from positron annihilation (when a positron interacts with an electron) are detected by imaging devices, allowing for visualization of the distribution of the radiotracer within the body.
therapeutic nuclear medicine
In ____, the energy deposited by high-energy electrons from a radioactive source can be used to target and destroy cancerous tissues
PHOTOELECTRIC INTERACTION
COMPTOON SCATTERING
PAOR PRODUCTION
PHOTON INTERACTION WITH MATTER
ANATOMIC IMAGING
which uses medical imaging technology to visualize the structure of the body and its organs
ANATOMIC IMAGING
has been the fundamental approach to cancer imaging for more than 100 years.
ANATOMIC IMAGING
with ____, we often do not know whether masses are the result of malignant or benign etiologies, as in solitary pulmonary nodules or borderline-size lymph nodes.
anatomic methods
Similarly, small cancers are undetectable with traditional ____, because they have not yet formed a mass.
anatomic methods
After surgery, it is even more difficult to assess for the presence of recurrent tumor with
anatomic methods
do not predict cancer response to treatment and do not quickly document tumors that are responding to therapy. Despite these challenges, anatomic images remain routine in cancer management.
MOLECULAR IMAGING
can be defined as "the visual representation, characterization and quantification of biological processes at the cellular and subcellular level."
MOLECULAR IMAGING
which is used to visualize structural abnormalities that are usually already the endpoint of the underlying molecular process.
molecular imaging technique
Nuclear medicine using radiation as a signal is a ____ that involves administration of a radioactive probe (a radiopharmaceutical) to a living subject, followed by noninvasive detection of the distribution of the radioactive probe; thus information related to biological and/or pathological functions that involve accumulation of the radioactive probe can be obtained
ANATOMIC IMAGING
Provides detailed images of the anatomy, helping diagnose conditions based on structural appearance
MOLECULAR IMAGING
Reveals how well organs and tissues are functioning
