non-ionising
and ionising
radiation
P1 Explain how the principles and production of non-ionising radiation technologies are used in medical
applications.
P2 Explain why non-ionising radiation technologies are used for diagnosis and treatment of the human
body.
P3 Explain how the principles and production of ionising radiation technologies are used in medical
applications.
P4 Explain why ionising radiation technologies are used for diagnosis and treatment of the human
body.
M1 Compare the principles, production and uses of different non-ionising radiation techniques in
medical applications.
M2 Compare the principles, production and uses of different ionising radiation techniques in medical
applications.
,Medical uses of non-ionising and ionising radiation
Non-ionising
Non-ionising radiation is a type of electromagnetic radiation
that does not have enough energy to ionise atoms in living
tissue. Ultraviolet radiation, visible light, microwaves,
radiation radiowaves, and infrared radiation are all forms of non-
ionising radiation as they have low energies (frequencies).
Some technologies utilise non-ionising radiation, including
ultrasound and MRI (Magnetic Resonance Imaging).
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,Ultrasound
Principles
• Form of imaging technique
• Uses high-frequency sound waves to
generate an image
• Piezoelectric effect, where an electric
current passes through a cable to the
transducer and is applied to the
crystals, causing them to deform and
vibrate, producing the ultrasound
beam
• Different types of ultrasound include
external (e.g. fetus screening),
internal (e.g. detailed screening of
organs) and endoscopic scan (e.g.
screening of stomach using
endoscope)
Medical uses of non-ionising and ionising radiation 3
, Ultrasound
Production
A transducer (probe) is pressed against the stomach which transmits high-frequency (1
to 5 megahertz) sound waves into the body
Sound waves travel into the body and hit a boundary between tissues
Some of the sound waves get reflected back to the transducer, while some travel on
further until they reach another boundary and get reflected
When these sound waves (echoes) hit the transducer, they generate electrical signals
that are sent to the ultrasound scanner
The scanner calculates the distance from the transducer to the tissue boundary using the
speed of sound in tissue (5,005 ft/s or1,540 m/s) and the time of the each echo's return ,
these distances are then used to generate a two-dimensional image of the baby during
pregnancy
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