Computed Tomography (CT)

Question 1

tomography

Answer 1

obtaining an image of a slice (or plane) through a patient

Question 2

the simplest form of tomography

Answer 2

linear tomography

Question 3

how does linear tomography work?

Answer 3

the x-ray head moves along a linear path and rotates so that the beam always passes through a fixed plane in the patient. the x-ray film is simultaneously moved so that the beam always falls at the same spot on the film.

Question 4

changing the relative position of the film and tube…

Answer 4

the focal point can be adjusted upward or downward

Question 5

transverse axial tomography

Answer 5

the x-ray tube and film is rotated around the whole body to produce a cross section

Question 6

why should patients be lying down?

Answer 6

it minimises movement

Question 7

computer assisted tomography

Answer 7

uses transverse axial tomography at a variety of different angles to create multiple cross-sectional slices of the patient - then combined to form a 3d image

Question 8

3d image in computer assisted tomography allows

Answer 8

the image to have the ability to visualise a combo of soft tissue, bone and blood vessels

Question 9

scans involving computer assisted tomography are…

Answer 9

CT (computed tomography) or CAT (computer axial tomography)

Question 10

what provides an adequate system for diagnosis in the main body sections

Answer 10

x-rays combined with ultrasound

Question 11

which regions in the body need a high density resolution of the CT scan

Answer 11

pancreas and lungs

Question 12

in a CT reconstruction process…

Answer 12

cross sections can be displayed in sequence or combined to form a 3D image to give a complete internal picture of the patient’s anatomy

Question 13

the basic CT reconstruction process - need to find the different density’s in a 2D block

Answer 13

simulate several scans of a 2D block, to see how we could attempt to use the scans to reconstruct the original image