X rays theory
Monday, 9 May 2022 5:53 pm
explain the principles of the production of X-rays:
Electrons are emitted from a heated filament (cathode).
Electrons are acceleration through a very high p.d between cathode and anode. (20kV to 10
Electrons are bombarded onto the metal target (the anode). As they decelerate the X-ray p
The photons of X-ray leave through a window.
High-speed electrons are incident on a metal target. The spectrum of the emitted X-ray ra
, CT scan theory
Monday, 9 May 2022 5:53 pm
Briefly explain the principles of CT scanning.?
X-ray taken of slice / plane / section
repeated at different angles
images / data is processed
combined / added to give (2-D) image of slice
repeated for successive slices
to build up a 3-D image
image can be viewed from different angles / rotated
Describe how the image produced during CT scanning differs from that produced by X-ray im
X-ray image is flat OR 2-dimensional
CT scan takes many images of a slice at different angles
these build up an image of a slice through the body
series of images of slices is made
so that 3D image can be built up
image can then be rotated
State one advantage and one disadvantage of producing a CT scan image of a person rather
advantage: image gives depth / image is 3D / final image can be viewed from any angle
disadvantage: greater exposure / more risk to health / more expensive / person must remain
suggest why
(i) CT scanning was not possible before fast computers with large memories were available,
combining of images involves (very) large number of calculations
(ii) the radiation dose for a CT scan is much larger than for an X-ray image of a leg bone.
CT scan consists of (very) many (single X-ray) images
Monday, 9 May 2022 5:53 pm
explain the principles of the production of X-rays:
Electrons are emitted from a heated filament (cathode).
Electrons are acceleration through a very high p.d between cathode and anode. (20kV to 10
Electrons are bombarded onto the metal target (the anode). As they decelerate the X-ray p
The photons of X-ray leave through a window.
High-speed electrons are incident on a metal target. The spectrum of the emitted X-ray ra
, CT scan theory
Monday, 9 May 2022 5:53 pm
Briefly explain the principles of CT scanning.?
X-ray taken of slice / plane / section
repeated at different angles
images / data is processed
combined / added to give (2-D) image of slice
repeated for successive slices
to build up a 3-D image
image can be viewed from different angles / rotated
Describe how the image produced during CT scanning differs from that produced by X-ray im
X-ray image is flat OR 2-dimensional
CT scan takes many images of a slice at different angles
these build up an image of a slice through the body
series of images of slices is made
so that 3D image can be built up
image can then be rotated
State one advantage and one disadvantage of producing a CT scan image of a person rather
advantage: image gives depth / image is 3D / final image can be viewed from any angle
disadvantage: greater exposure / more risk to health / more expensive / person must remain
suggest why
(i) CT scanning was not possible before fast computers with large memories were available,
combining of images involves (very) large number of calculations
(ii) the radiation dose for a CT scan is much larger than for an X-ray image of a leg bone.
CT scan consists of (very) many (single X-ray) images
