Flashcards in X-rays and ultrasound Deck (8)
What are x-rays?
very short wavelength - same as the diameter of an atom
cause ionisation - adding and removing electrons in atoms
What are the properties of x-rays that make it useful in medicine?
affect photographic film in the same way as light - turning it black
absorbed by metal and bone
transmitted (pass through) by soft tissue
What are CCDs?
charge-coupled device allow images to be formed electronically
allow images to be recorded and stored more easily
What are CT scans?
computerised tomography scans involve taking a range of x-ray images from various positions
processed by a computer to build a 3D image
allows the doctors to view different structure and layers in the body
What precautions must we take when using x-rays?
x-ray machines are usually low energy to prevent damage
patients are limited to the amount of x-rays they are allowed to have
x-ray rooms have lead walls to protect people outside and staff
What are ultrasound waves?
electronic systems produce ultrasound waves that have a higher frequency than what humans can hear (above 20,000Hz)
What are the properties of ultrasound waves that make them useful in medicine?
partially reflected when they meet a boundary between two different media
the time taken for the reflection to reach a detector can be used to determine the distance from the boundary
e.g. used in pre-natal scanning and removal of kidney stones