Nuclear Medicine Flashcards
What is nuclear medicine?
Planar image it’s very foggy compare to other imaging modalities
It combines anatomy physiology, chemistry, physics, maths, computing
Clinical information drive from observing the distribution of a pharmaceutical
Why is nuclear medicine used and why hybrid?
It can asses the function and answer questions
Compare to other modalities MRI and CT can show anatomy in great detail but can’t assess the function
Hybrid imaging in nuclear medicine can assess function and anatomy
Why would we want to know the function?
And what can it tell us about function?
So that we can find a good course for treatment
Nuclear medicine provides us with quantifiable functional imaging – measure of how well/not well something is working
Example:
Which kidneys work in the hardest
How effective is the left ventricle working
What does a gallbladder do when you eat
What is the mobility in your digestive system
What kind of radiation does nuclear medicine use?
Gamma radiation 140 kev – High energy electromagnetic radiation given off by anatomic nucleus undergoing radioactive decay
It has a high penetration so it would go through lead apron so need to protect yourself another ways
Where does the gamma radiation come from in nuclear imaging?
99mTC - metastable isotope of technetium
Why did decays returns to a stable state and in the process it emits a gamma ray
Radio isotopes in nuclear imaging:
Uranium in nuclear power station ( specialised facility to produce MO99)
Can be made into MO98 (absorbs neutrons) it is then blasted and made into MO99
MO99 is then manufactured into a generator for delivery to the hospital
What process is taken when MO99 gets to hospital pharmacy?
MO99 put into technetium generator - milking
Aliminium oxide attracts MO - where as technetium is not
MO99 into TC?
MO99 has a half life of 67 hours and decays to form Technetium-99m by particle emission
Tc-99m - half life 6 hours
What is half life?
Physical half life - length of time it takes for a radioactive substance to decay to half its level of activity
 biological half-life – length of time it takes for the body to flush it out
Physical and biological combined are called the effective half life
The gamma camera?
Radiation goes through patient through a colimater which acts as a grid
Radiation then hits photosensitive crystals and produces light
PMT converts light to an electrical signal which is then displayed
Nuclear medicine collimator– nuclear medicines version of grid
Lead plate with holes
Resolution is better when patient is close to collimator- most scatter can be prevented
Low, Medium, and high energy collimators
Gamma camera/scintillation camera?
Dual head gamma camera
Control panel
Powered
Sodium iodide crystals
Controlling the distributation of radioactive tracer?
Label the isotope
This is done by radiopharmacists in the morning - use worklist
Combine the isotope with something that is found naturally/metabolised in the specific organ you’re wanting to image
 cold and hotspots?
Areas of hypo and hyper metabolic rate
Less or more radio isotope found in area
Cold - less
Hot - more - bad
Good characteristics of radio isotopes used in nuclear medicine for imaging?
Good half life – increase dose to patient if it’s too long though
Type of energy emission – gamma 50 to 300 kv
Emits no other particles in the decay process – reduce radiation dose
Taken up rapidly in the area of interest and excreted with ease
easily produced, unlabelled
And low cost
The radiographers role in nuclear imaging?
Some radiation protection:
Custom drop objection – premade for you
Lead lined pot – Ladbrokes - lead glass
Syringe has a lead glass – lead bin for used syringes
Cannulations and injection
Patient communication
Use of equipment
Process images
What is the 4 point safety check:
Radiopharmacy customises pharmaceutical for each patient
Patient information – measure and record radiation level
 A different radiographer verifies the same information
Check the vial + draw the injection record radiation level
ID the patient - explain exam - inject the patient and record the doors - this is done by a different radiographer

Different scanning techniques for nuclear medicine:
Planar - only ap and pa
Dynamic - watching real time - quantifiable
SPECT - Lung - ventilation + perfusion
SPECT - CT - HMPAO brain
Therapeutic application Of radiopharmaceuticals;
Can be used to treat cancer

What is PET?
Positron emission tomography
Tomographic technique
Non-invasive quantities assessment of biochemical and functional processes
PET-CT hybrid
What is a positron?
An atom consists of a nucleus consisting proton and neutron and encircling electrons
Photons constantly change back to proton - Within the nucleus
Positrons are emitted when you cry has too many protons to achieve stability
How do you make a positron?
Made in a particle Excelerator called a cyclotron
Items are bombarded with protons and of the closest tries to return disability a positron is ejected (decay)
What is antimatter and Annihilation?
When a low energy electron collides with a low energy positron they both annihilate each other and this destruction is converted into energy in the form of two photons (gamma ray)
The pet scanner
The detected array registers both gamma rays that are emitted
Information is used to build up a picture of where they are coming from – pooling
Anatomical data is acquired by the CT scan
What is the most commonly used isotope in pet?
Fluoro–deoxy –glucose
Half life – 110 minutes
Cell metabolism loves glucose
Increased rate - cancerous - hot spot
Injecting FDG?
Medead FDG injector:
connect to work list
calculate dose based on weight and height
Reduced staff dose
Patient preparation:
99% oncology work:
Ensure they are hydrated relaxed and have fasted for at least six hours
IV inject 18 – FDG
One hour uptake in a darkened room
Void bladder prior to scan
Hybrid scan whole body pet – city
20 to 30 minutes scan
results within 48 hours
