section 1 multiple choice

Question 1

with regard to radiation protection, if a patient received an absorbed dose of 64mGy at 1m from the source, what does would they receive at 2m?

Answer 1

16mGy

Question 2

with regard to computed tomography (CT), what happens when the slice thickness is decreased

Answer 2

Spatial resolution decreases and SNR decreases but radiation dose increases

Question 3

with regard to CT, which statement is true about the use iterative reconstruction rather than filtered back projection

Answer 3

Spatial resolution increases and radiation dose decreases

Question 4

If a radionuclide has a physical half-life of 6 hours and the initial dose is measured as 300 MBq, what will be the activity of the dose after twelve hours?

Answer 4

75 MBq

Question 5

With regard to Positron Emission Tomography (PET), what is the energy of the two gamma photons produced as a result of pair production:

Answer 5

511keV

Question 6

With regard to diagnostic ultrasound, increasing frequency will have the following effect on image quality:

Answer 6

Decrease penetration and increase resolution

Question 7

With regard to diagnostic ultrasound, which ONE of the following values best represents the speed of sound (m/s) though fat:

Answer 7

1460m/s

Question 8

With regard to Magnetic Resonance Imaging (MRI) bioeffects and safety, which ONE of the following can MOST affect a patient with a pacemaker:

Answer 8

Static Magnetic field

Question 9

With regard to MRI and spin echo pulse sequencing, which ONE of the following Time to Echo (TE) and Time between Repetitions (TR) sequences will maximise T2 weighting:

Answer 9

A long TE and a long TR

Question 10

Which ONE of the following is a non-ionising radiation biological effect:
Hormesis

Cavitation

Cataract formation

Teratogenesis

Answer 10

Cavitation