Imaging in Inflammatory Diseases and Infection

Question 1

What does molecular imaging consist of

Answer 1

Radionuclide imaging
Positron emission tomography
Magnetic resonance imaging
Optical imaging

Question 2

How does radionuclide imaging occur

Answer 2

Gamma rays are beamed into the patient who transmits them back out
They go to the lead collimator gamma camera

Question 3

What is radiography

Answer 3

X-rays being beamed through a x-ray tube to the patient to form a digital image capture

Question 4

How do gamma rays occur

Answer 4

From the radioactive decay of unstable isotopes

Question 5

State 3 features of gamma rays

Answer 5

High energy
High frequency (approx 10^20 waves per second)
Similar properties to x-rays

Question 6

What are radiopharmaceuticals

Answer 6

Drugs with a:
Radioactive element
Pharmacetuical element

Question 7

State 7 properties the ideal isotope should have

Answer 7

A half-life similar to the length of examination
Emmitt gamma instead of α or β
The energy of γ rays should be between 50-300 keV
The radionuclide should be readily available at the hospital site
Should be easily bound to a pharmaceutical component
The radiopharmaceutical should be simple to prepare
The radiopharmaceutical should be eliminated in a similar half-time to the duration of the examination

Question 8

Give 4 examples of ideal isotopes

Answer 8

Hydroxy-diphosphonate for the bone
Dimercapto-succinic acid for the kidney
Hexamethyl-propine amine oxime for the brain
Macroaggregated albumin for the lung

Question 9

How does a gamma camera produce an image

Answer 9

Nuclear energy will be released from inside the radioactive nucleus
Gamma ray emitted from the patient known as gamma electromagnetic energy
Image crystal (NaI) produces flashes of light known as light electromagnetic energy
This is converted into electrical energy to display the image.

Question 10

What does SPECT stand for

Answer 10

Single photon emission computed tomography

Question 11

What is the image quality of the gamma camera dependent on

Answer 11

Radiation dose (limits are in place)
Collimator
Metal objects
Proximity of area of interest to camera

Question 12

What is SPECT

Answer 12

A CT version of nuclear medicine where the gamma camera rotates around the area of interest

Question 13

What is SPECT mainly used for

Answer 13

Brain and cardiac studies

But can be applied to any site of interest in other studies

Question 14

Gives examples of other studies SPECT can be used for

Answer 14

Spine in bone scan

Lung scintigraphy

Question 15

What does PET stand for

Answer 15

Positron emission tomography

Question 16

What is PET

Answer 16

A form of molecular imaging which uses radionuclides that decay by positron

Question 17

What is PET used for

Answer 17

Produce images of biologically interesting processes

For absolute quantitation

Question 18

State a negative feature of PET

Answer 18

Requires arterial sampling

Question 19

How is a PET image produced

Answer 19

Positron emission releases gamma rays which are detected by a detector in the imaging ring and enter the coincidence circuit to produce an image

Question 20

Name 4 PET radionuclides and their half lives

Answer 20

18^F - 110 minutes
11^C - 20 minutes
13^N - 10 minutes
15^O - 2 minutes

Question 21

What does 18^fluorodeoxy glucose (FDG) do

Answer 21

It takes the place of glucose to produce 18^FDG-6-P

Question 22

Where is FDG taken up physiologically

Answer 22

Brain
Myocardium
Stomach
Liver
Spleen
Colon 
Urinary tract

Question 23

What are the risks of radiation

Answer 23

Ionising radiation
Inducing fatal cancer
Cost
Risk to patients and staff

Question 24

What are the benefits of radiation

Answer 24

Diagnosis of disease
Management change
Treatment