X-rays in Medicine Flashcards
Are X-rays ionising?
Yes!
X-rays are [ ] frequency, [ ] wavelength electromagnetic waves. Their wave length is roughly the same size as the diameter of an [ ].
high
short
atom
What are X-rays transmitted by (pass through)?
healthy tissue
What are X-rays absorbed by?
denser materials;
bones and metal
What medical conditions can X-rays be used to identify?
Bone fractures or dental problems
X-rays affect photographic film in the same way as [ ]. therefore they an be used to take photographs.
light
X-ray images can be formed electronically using [ }
Charge-coupled devices (CCDs)
What is a CCD?
Charge-coupled devices are silicon chips, divided up into a grid of millions off identical pixels.
How do CCDs work?
CCDs detect X-rays and produce electronic signals which are used to form high resolution images.
What machine uses X-rays to produce high resolution images of sfot and hard tissue.
CT (Computerised axial tomography)
What is the procedure for the patient for a CT scan?
The patient is put inside the cylindrical scanner, and an X-ray beam is fired through the body from an X-ray tube and picked up by detectors on the opposite side. The x-ray tube and detectors are rotated during the scan.
How does the CT scanner create an image?
A computer interprets the signals from the detectors to form an image of a 2D slice through the body. Multiple 2D CT scans can be put together to make a 3D image of the inside of the body.
What can high doses of X-rays cause?
Cause living cells to die
How can you treat cancer with X-rays?
1) The x-rays are focused on the tumour using a wide beam
2) This beam is rotated around the patient with the tumour at the centre
3) This minimises the exposure of normal cells to radiation, and so reduces the chances of damaging the rest of the body
What do radiographers do to reduce the X-ray dose they receive? (3)
Wear lead aprons
Stand behind a Lead screen
Leave the room while scans are being done
