X-Rays And Ultrasound Flashcards
What feature allows X-rays to penetrate healthy tissue but be absorbed by bone?
Short Wavelength
How do CT scans work?
Multiple X-Rays build up a 3d image of the patient
What is a medical use of X-Rays (Not imaging)
Ionising radiation can be used to treat cancer (Radiotherapy)
Name two precautions radiographers use to protect themselves from the ionising radiation of X-rays
Standing behind a lead screen, leaving the room whilst the x-ray is occurring
Give a short definition of ultrasound:
Sound waves above the human range of hearing (20,000 Hz)
When ultrasound reaches a boundary between media, what happens to the wave?
Some is refracted, and some is partially reflected back.
How is ultrasound used in industry?
To detect cracks in floors
How is ultrasound used medically (other than in medical imaging)
To break down kidney stones
Why can a baby not be x-rayed?
The dose of radiation could cause cancer to develop in the unborn babies cells
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)
1500x0. 00001=0.015m
0. 015/2= 0.0075m
7. 5mm.