X-rays/CT scan/Ultra Sound Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

CT X

A

X-Ray: Series of x-ray images

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

CT A

A

Angles: Different angles are used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

CT I

A

Image: To give the image of the slice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

CT S

A

Slice: Repeated for many different slices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

CT 3

A

3D: To build a 3D image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Formula for half life

A

Half life = ln(2) / decay constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Formula for activity

A

A = Decay Constant * Number of undecided

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are x-rays produced?

A

Metal target bombarded with electrons, when ever a particle is accelerated it emits electromagnetic radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

X-ray ratio between acceleration and wavelength

A

Inversely proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

X-rays are emitted from?

A

The heated cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

X-rays: How is intensity controlled?

A

Controlling rate of arrival of electrons at the anode by controlling the heat of the cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

X-rays: How is hardness controlled?

A

Potential Difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

X-rays: How is sharpness controlled?

A

X-ray beam width, inversely proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

X-rays: What are soft x-rays?

A

Set of peaks at longer wavelengths that don’t add to the image but increase background radiation, absorbed by using a aluminium window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

X-rays: What absorbs more bone or muscle?

A

Bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Formula for attenuation of X-rays

A

I = I * e ^-yx where y is a constant

17
Q

What is HVT

A

Half value thickness, depth required to reduce intensity by one half

18
Q

Steps for working out CT scan

A

Remove background, divide by number of scans-1

19
Q

Formula for acoustic impedance

A

Z = pc where c is the speed of sound in a medium

20
Q

What is acoustic impedance

A

The resistance sound waves encounter in a medium

21
Q

Formula for intensity at a certain depth

A

I = I * e ^ -kx where k is the absorption constant

22
Q

What is ultrasound used for

A

To gather information about internal structures of the body

23
Q

How does ultrasound work

A

Monitoring pulses of ultrasound are sent into the body at regular intervals, the ultrasound is reflected on large changes in acoustic impedance, this reflected sound is mapped based on the time it took to return which produces an image

24
Q

Why is cellulose gel used

A

To limit the large change of acoustic impedance at the boundary

25
Q

What is an A-Scan

A

Distance, time and strength of reflected sound waves are used to map using a transducer and a C.R.O

26
Q

What is a B-Scan

A

Multiple A-Scans put together to build a 2-D image