X-Rays And Ultrasound

Question 1

What feature allows X-rays to penetrate healthy tissue but be absorbed by bone?

Answer 1

Short Wavelength

Question 2

How do CT scans work?

Answer 2

Multiple X-Rays build up a 3d image of the patient

Question 3

What is a medical use of X-Rays (Not imaging)

Answer 3

Ionising radiation can be used to treat cancer (Radiotherapy)

Question 4

Name two precautions radiographers use to protect themselves from the ionising radiation of X-rays

Answer 4

Standing behind a lead screen, leaving the room whilst the x-ray is occurring

Question 5

Give a short definition of ultrasound:

Answer 5

Sound waves above the human range of hearing (20,000 Hz)

Question 6

When ultrasound reaches a boundary between media, what happens to the wave?

Answer 6

Some is refracted, and some is partially reflected back.

Question 7

How is ultrasound used in industry?

Answer 7

To detect cracks in floors

Question 8

How is ultrasound used medically (other than in medical imaging)

Answer 8

To break down kidney stones

Question 9

Why can a baby not be x-rayed?

Answer 9

The dose of radiation could cause cancer to develop in the unborn babies cells

Question 10

An oscilloscope trace shows that the time between the reflected pulses is 0.00001 seconds. The ultrasound travels at 100m/s. Calculate the distance between the two boundaries.
S=VxT (Distance=SpeedxTime)

Answer 10

1500x0. 00001=0.015m
0. 015/2= 0.0075m
7. 5mm.