IMPCB - Nuclear Medical Physics

What scintillation camera acquisition mode stores counts sequentially with x,y coordinates and time markers?

• 
  

• • Cartesian Mode

• List Mode

• • Cine Mode

• • Frame Mode

Below is an image and profile of a uniform intensity SPECT phantom. Why does the phantom not appear uniform?

• • A bowtie filter was used

• There is no attenuation correction

• • A bowtie filter was not used

• • An insufficient number of projections were used

Which of the following will not decrease collimator blurring in SPECT imaging?

• Decreasing septal thickness
  

• • Increasing collimator hole length

• • Decreasing collimator hole diameter

Which of the following is not a SPECT acquisition parameter?

• Time of flight window

• • Time per projection

• • Degrees per step and stop

• • Degrees of rotation

What is the energy of a Tc-99m photon?

• • 58 keV

• • 1.25 MeV

• 140 keV

• • 511 keV

What do PET scanners detect?

• • Protons emitted after positron decay in regions of high uptake

• • NaI(Tl) scintillation events

• Annihilation photons

• • Positrons emitted from radiolabeled biologically available chemicals such as FDG

PET crystals are often thicker and denser than those used in gamma cameras. Why is this?

• PET annihilation photons are higher energy than the photons detected via gamma camera

• • Large crystals improve geometric efficiency

• • PET uses time of flight information to determine point of photon emission. Therefore a small detector is unnecessary

• • PET reconstruction requires much higher collection efficiency

F-18 decays with a maximum positron energy of 0.63MeV and O-15 decays with a maximum positron energy of 1.74MeV. Which radionuclide provides the greater uptake localization accuracy?

• F-18

• The solution depends on the carrier molecule

• • O-15

• • Both produce the same error

A patient preparing for a PET study has been advised by a friend, a local physics teacher, to remove his clothes during his PET scan. What effect would this have on the scan?

• • Improve SNR

• No impact on scan

• • Decrease scan time

• • Improve spatial resolution

Why do PET/CT devices include the CT component?

• • CT imaging requires the same physical hardware at PET, so the marginal cost of a combined system is very low

• The linear attenuation coefficient data can be used to create a more accurate PET image

• • PET images cannot be generated without the filtered back projection data provided by a CT

• • This allows for direct use of the PET/CT in treatment planning