P3- X Rays in Medicine Flashcards
How are X Rays used to kill cancer cells? How does this minimise the damage to normal body cells?
They’re carefully focussed and at just the right dosage to kill the cancer cells without damaging too many normal cells.
1) focussed on tumour using a wide beam
2) beam is rotated around the patient with tumour at the centre
3) this minimises the exposure of normal cells to radiation, and so reduces the chances of damaging rest of body.
What does CT scan stand for?
Computerised axial tomography
X Rays can cause i……….
Ionisation
X Rays can be used to treat ………. just like gamma radiation.
Cancers
X Rays affect photographic film in the same way as …….. So they can be used to take photographs
Light
Why are X Rays and CT scans not used to scan babies in the womb?
Ionising
CT scans use even more X Ray radiation than standard X Rays
How do CT scans work?
Use x rays to produce high resolution images of soft and hard tissue.
Patient put into cylindrical tube
X Ray beam fired through body from an X Ray tube and picked up by detectors on the opposite side.
Tube and detectors are rotated during the scan.
A two dimensional slice through the body is formed. Multiple can be put together to make a 3d image.
What is a CCD?
Charge-coupled device
Silicon chips about the size of a postage stamp, divided up into a grid of millions of identical pixels
They detect X rays and produce electronic signals which are used to form high resolution images. This same technology used in cameras
In ionisation high doses of X Rays will …….
Kill living cells
How can CT scans form a 3d image?
By taking multiple 2D images
Radiographers take precautions to minimise ……………. …….
Radiation dose (from X Rays and CT scans)
What are X Rays?
High frequency, short wavelength EM waves used in hospitals for medical diagnosis
What are the parts of a CT scan machine?
X Ray tube
Detectors
X Rays are ……….. by healthy tissue, but are ……….. by denser material like bones and metals
Transmitted
Absorbed
…. Scans use X Rays
CT
