Nuclear Medicine

Question 1

What is nuclear medicine?

Answer 1

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

Question 2

Why is nuclear medicine used and why hybrid?

Answer 2

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

Question 3

Why would we want to know the function?
And what can it tell us about function?

Answer 3

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

Question 4

What kind of radiation does nuclear medicine use?

Answer 4

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

Question 5

Where does the gamma radiation come from in nuclear imaging?

Answer 5

99mTC - metastable isotope of technetium
Why did decays returns to a stable state and in the process it emits a gamma ray

Question 6

Radio isotopes in nuclear imaging:

Answer 6

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

Question 7

What process is taken when MO99 gets to hospital pharmacy?

Answer 7

MO99 put into technetium generator - milking
Aliminium oxide attracts MO - where as technetium is not

Question 8

MO99 into TC?

Answer 8

MO99 has a half life of 67 hours and decays to form Technetium-99m by particle emission

Tc-99m - half life 6 hours

Question 9

What is half life?

Answer 9

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

Question 10

The gamma camera?

Answer 10

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

Question 11

Nuclear medicine collimator– nuclear medicines version of grid

Answer 11

Lead plate with holes

Resolution is better when patient is close to collimator- most scatter can be prevented

Low, Medium, and high energy collimators

Question 12

Gamma camera/scintillation camera?

Answer 12

Dual head gamma camera

Control panel

Powered

Sodium iodide crystals

Question 13

Controlling the distributation of radioactive tracer?

Answer 13

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

Question 14

 cold and hotspots?

Answer 14

Areas of hypo and hyper metabolic rate

Less or more radio isotope found in area

Cold - less
Hot - more - bad

Question 15

Good characteristics of radio isotopes used in nuclear medicine for imaging?

Answer 15

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

Question 16

The radiographers role in nuclear imaging?
Some radiation protection:

Answer 16

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

Question 17

What is the 4 point safety check:

Answer 17

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



Question 18

Different scanning techniques for nuclear medicine:

Answer 18

Planar - only ap and pa

Dynamic - watching real time - quantifiable

SPECT - Lung - ventilation + perfusion

SPECT - CT - HMPAO brain

Question 19

Therapeutic application Of radiopharmaceuticals;

Answer 19

Can be used to treat cancer


Question 20

What is PET?

Answer 20

Positron emission tomography

Tomographic technique

Non-invasive quantities assessment of biochemical and functional processes

PET-CT hybrid

Question 21

What is a positron?

Answer 21

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

Question 22

How do you make a positron?

Answer 22

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)

Question 23

What is antimatter and Annihilation?

Answer 23

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)

Question 24

The pet scanner

Answer 24

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

Question 25

What is the most commonly used isotope in pet?

Answer 25

Fluoro–deoxy –glucose

Half life – 110 minutes

Cell metabolism loves glucose
Increased rate - cancerous - hot spot

Question 26

Injecting FDG?

Answer 26

Medead FDG injector:
connect to work list
calculate dose based on weight and height
Reduced staff dose

Question 27

Patient preparation:

Answer 27

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