ACCURATE ANSWERS |VERIFIED
Where are x-rays made? - ACCURATE ANSWERS✔✔ in the electron
shell structure of an atom
What is Bremsstrahlung radiation? - ACCURATE ANSWERS✔✔
energetic electrons pass very near the nucleus of an atom. The strong
forces of th positive charged atom causes the negatively charged electron
to decelerate; the path of the electron is changed, and some of the kinetic
energy of the electron is lost, and converted into x-rays
what is characteristic x-ray radiation? - ACCURATE ANSWERS✔✔
following the ionization of an atom that leaves an inner shell, outer shell
electrons drop down to refill the inner shell. As these electrons drop
down, they lose energy, which is released as x-rays.
What does pre-collimation do? - ACCURATE ANSWERS✔✔ (used
before x-rays enter the patient) defines the beam shape and width (which
is usually fan or cone shaped) and protects the patient from excess
radiation
What does post-collimation do? - ACCURATE ANSWERS✔✔ (used to
reduce scatter after leaving the patient) is used before the radiation
strikes the detectors
, What are advantages of thinner collimation? - ACCURATE
ANSWERS✔✔ A: less volume averaging
B: increased spatial resolution
C: decreased spatial resolution
D: fewer artifacts
E: all of the above
F: a,b,d **
True or false: in CT, the gantry rotates continuously in one direction on a
slip ring system - ACCURATE ANSWERS✔✔ true
What is a scout imaged used for? - ACCURATE ANSWERS✔✔
Positioning /localization
Pitch - ACCURATE ANSWERS✔✔ the ratio of patient's movements
through the gantry during one 360 degree beam rotation relative to the
beam collimation (in single slice CT)
The table distance traveled in 1 gantry rotation of 360o divided by the
total thickness of all acquired slices—in multi detector CT
How is pitch calculated? - ACCURATE ANSWERS✔✔ pitch = table
movement per rotation (mm)/ (number of slices)(slices width in mm)