Imaging in Inflammatory Diseases and Infection Flashcards Preview

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Flashcards in Imaging in Inflammatory Diseases and Infection Deck (24)
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1

What does molecular imaging consist of

Radionuclide imaging
Positron emission tomography
Magnetic resonance imaging
Optical imaging

2

How does radionuclide imaging occur

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

3

What is radiography

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

4

How do gamma rays occur

From the radioactive decay of unstable isotopes

5

State 3 features of gamma rays

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

6

What are radiopharmaceuticals

Drugs with a:
Radioactive element
Pharmacetuical element

7

State 7 properties the ideal isotope should have

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

8

Give 4 examples of ideal isotopes

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

9

How does a gamma camera produce an image

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.

10

What does SPECT stand for

Single photon emission computed tomography

11

What is the image quality of the gamma camera dependent on

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

12

What is SPECT

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

13

What is SPECT mainly used for

Brain and cardiac studies

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

14

Gives examples of other studies SPECT can be used for

Spine in bone scan
Lung scintigraphy

15

What does PET stand for

Positron emission tomography

16

What is PET

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

17

What is PET used for

Produce images of biologically interesting processes
For absolute quantitation

18

State a negative feature of PET

Requires arterial sampling

19

How is a PET image produced

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

20

Name 4 PET radionuclides and their half lives

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

21

What does 18^fluorodeoxy glucose (FDG) do

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

22

Where is FDG taken up physiologically

Brain
Myocardium
Stomach
Liver
Spleen
Colon
Urinary tract

23

What are the risks of radiation

Ionising radiation
Inducing fatal cancer
Cost
Risk to patients and staff

24

What are the benefits of radiation

Diagnosis of disease
Management change
Treatment