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Flashcards in Imaging of head and neck Deck (6)
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1

How do CT scans work?

X-ray source
X-rays pass through tissues
detector on opposite side

detector picks up varying amounts of X-rays depending on density of tissue structures

2

How does the density of tissues affect X-rays passing through them?

Denser tissue
more X-rays absorbed, fewer X-rays pass through to detector

Less dense tissue
fewer X-rays absorbed, more X-rays pass through to the detector

3

How does the amount of X-rays passing through the tissue affect the CT image?

Fewer X-rays absorbed, more X-rays passed through to detector, darker on image

More X-rays absorbed, fewer X-rays passed through to detector, lighter on image

4

What is the order of the following tissues from most dense to least dense
-fluid
-bone
-fat
-soft tissue and blood

Bone

Soft tissue and blood

Fluid

Fat

5

What is the advantage of CT over plain X-rays?

Can better differentiate between subtle differences in density of different tissues

6

What are the advantages of plain radiography?

Cheap

Readily available

Low radiation

Visualising bony structures