39. NUCLEAR MEDICINE Flashcards
1
Q
- What does Nuclear Medicine consist of?
A
- it consists of a range of diagnostic and therapeutic
procedures
2
Q
- What do these diagnostic and therapeutic procedures make sure of?
A
- Radioisotopes
3
Q
- Why do they make use of Radioisotopes?
A
- these can penetrate tissue
- they can be detected by the outside body
- their distribution throughout the body can be
determined
4
Q
- When can we use Beta (β) Particle emitters?
A
- when the diagnostic test involves measuring samples
- these are taken from a patient
5
Q
- What kind of particle emission is more desirable when we are dealing with therapeutic work?
A
- the emission of Beta Particles
6
Q
- List 2 reasons as to why Beta Particles are preferred?
A
- They have a short range in tissue
- They an deliver high radiation doses
(this is due to the location of the radioisotope)
7
Q
- What do we use Radio-iodine (I¹³³) for?
A
- Thyroid Gland Treatments
8
Q
- What can be said about the absorption of Gamma Rays by the Human Body?
A
- they are extremely strong
- these rays do not get absorbed by the human body
- they simply pass through
9
Q
- What can be said about the absorption of Beta Rays by the Human Body?
A
- they are absorbed in the dermis
10
Q
- What can be said about the absorption of Alpha Rays by the Human Body?
A
- they are absorbed in the dermis
11
Q
- Who discovered natural radioactivity?
A
- Henri Becquerel
- he did this in 1896
12
Q
- What did Henri Becquerel explain?
A
- he explained the macroscopic kinetics of Radioactive
decay
13
Q
- Name the scientists that paved the way of Nuclear Medicine?
A
- Marie Sklodowska-Curie
- Pierre Curie
- Ernest Rutherford
- Frederick Soddy
14
Q
- How long did it take for the radioactive decay modes to be fully understood?
A
- several decades
15
Q
- Where can radioactive nuclides occur in?
A
THEY CAN OCCUR IN:
- nature
- they can be man made
16
Q
- What kind of stability do Radioactive Nuclides have?
A
- they are unstable
- they do not have the same number of protons and
neutrons - they try to reach more stable configurations
17
Q
- How do the Radioactive Nuclides reach more stable nuclear configurations?
A
- they do this through various processes of spontaneous
radioactive decay
18
Q
- List the 6 main categories of Radioactive Decay?
A
- Alpha (⍺) Decay
- Beta (β) Decay
- Gamma (y) Decay
- and Internal Conversion (IC) - Spontaneous Fission (SF)
- Proton Emission (PE) Decay
- Neutron Emission (NE) Decay
19
Q
- What usually accompanies Nuclear Transformations?
A
- the emission of energetic particles
20
Q
- There are many decay modes in which these energetic particles are released.
Name the first 6.
A
- Alpha (⍺) particles
- this happens through Alpha Decay - Electrons in Beta (β) - Decay
- Positrons in Beta (β) + Decay
- Neutrinos in Beta (β) + Decay
- Anti-neutrinos in Beta (β) - Decay
- Gamma (y) rays in Gamma (y) Decay
- these rays are electromagnetic
- they are similar to X-Rays
- they have more energy
21
Q
- There are many decay modes in which these energetic particles are released.
Name the next 4.
A
- Atomic Orbital Electrons in Internal Conversion (IC)
- Neutrons in Spontaneous Fission
- and in Neuton Emission Decay - Heavier nuclei in Spontaneous Fission
- Protons in Proton Emission
22
Q
- What is an Alpha Particle?
A
- it is a high energy Helium nuclei
- it consists of two protons
- it consists of two neutrons
23
Q
- What is a Beta Particle?
A
- these are high energy electrons
24
Q
- What is a Positron?
A
- these are particles with the same mass as an electron
- they have 1 unit of positive charge
25
Q
- What is a Proton?
A
- these are nuclei of Hydrogen atoms
26
Q
- What is a Neutron?
A
- these are particles with a mass that is approximately
equal to that of a proton - but it has no charge
27
Q
- What is a Gamma Ray?
A
- these is very high energy electromagnetic radiation
28
Q
- There are specific physical quantities that must be conserved in each nuclear transformation.
List all 5 of the most important ones.
A
- Total Energy
- Atomic Number
(Proton Number) - Momentum
- Charge
- Atomic Mass Number
(Number of nucleons)
29
Q
- How can Nuclear Stability be achieved in low
atomic (Z) elements?
A
NUCLEAR STABILITY IS ACHIEVED:
- when the number of neutrons (N) is approximately
equal to the number of protons (Z)
30
Q
- What happens to the ratio of Neutrons to Protons
(N/Z) as the atomic number increases?
A
- the N/Z ratio increases from 1
- to about 1.5
31
Q
- What happens when a nucleus has a N/Z that is too high for Nuclear Stability?
A
- there is an excess number of neutrons present
- a direct emission of a neutron is possible
- this is called Neutron Rich
32
Q
- What happens when a Nucleus is Neutron rich?
A
- it decays through a conversion
- this conversion is of a neutron into a proton
THIS CONVERSION EMITS:
- an electron
- an anti-neutrino
NB:
- this process is known as Beta (β) - Decay
33
Q
- What are some similarities between Neutrinos and Anti-Neutrinos?
A
- they are the same sub-particles
- they have no mass
- they have no charge
34
Q
- What is the difference between Neutrinos and Anti-Neutrinos?
A
- they have different spin
- this maintains angular momentum during Beta - Decay
35
Q
- What happens when the nucleus has a N/Z ratio that is too low for Nuclear Stability?
A
- there is an excess number of Protons
- this is known as proton Rich
36
Q
- What happens when the Nucleus is Proton Rich?
A
- it decays through a conversion
- this conversion is of a proton into a neutron
THIS EMITS:
- a positron
- a neutrino
NB:
- this process is called Beta (β) + Decay
37
Q
- If a nucleus does not undergo Beta (B) + Decay, what other process can is partake in?
A
- the nucleus may capture an orbital electron
- it transforms a proton into a neutron
- it emits a neutrino
THIS PROCESS IS KNOWN AS:
- Electron Capture
38
Q
- What other method is there, is the nucleus does not undergo Beta (B) + Decay nor Electron Capture?
A
- the direct emission of a proton
- this is less likely
UNLESS:
- the nuclear imbalance is very high
39
Q
- Does this diagram make sense?
A
- yes
40
Q
- Does this diagram make sense?
A
- yes
