NCT Quality Control & Equipment Assurance 2

Question 1

Center of rotation (COR) calibration in SPECT imaging is performed to:

Accepted Answer

Ensure the mechanical rotation center and the electronic center of the projection data are aligned

Answer

Measure the sensitivity of the detector at multiple angles

Answer

Verify that collimator holes are parallel to the detector face

Answer

Calibrate the injected activity against a dose calibrator

Question 2

How frequently should SPECT center of rotation calibration be performed under standard nuclear cardiology QC protocols?

Accepted Answer

Weekly

Answer

Daily

Answer

Monthly

Answer

Annually

Question 3

The recommended energy window for Tc-99m myocardial perfusion SPECT imaging is:

Accepted Answer

20% symmetric window centered at 140 keV

Answer

10% symmetric window centered at 140 keV

Answer

30% symmetric window centered at 140 keV

Answer

15% symmetric window centered at 159 keV

Question 4

Dead time in nuclear medicine instrumentation refers to:

Accepted Answer

The period after a detected event during which the system cannot register additional events

Answer

The time required for radioactive tracer to reach peak myocardial uptake

Answer

The delay between patient injection and SPECT acquisition start

Answer

The pause between detector rotation steps in step-and-shoot SPECT

Question 5

The multi-window spatial registration test evaluates whether:

Accepted Answer

Multiple energy peaks from different radionuclides are spatially co-registered on the detector

Answer

The camera can simultaneously acquire two patients at different energy windows

Answer

Energy window settings shift with changing room temperature

Answer

Flood field uniformity is maintained across all energy windows

Question 6

Gamma camera system sensitivity is typically expressed as:

Accepted Answer

Counts per second per megabecquerel (cps/MBq) or counts per minute per microcurie (cpm/µCi)

Answer

Millimeters of spatial resolution at 10 cm distance

Answer

Percentage of photons transmitted through the collimator

Answer

Ratio of scatter to primary counts in the energy window

Question 7

A SPECT uniformity correction flood is acquired to:

Accepted Answer

Generate a pixel-by-pixel correction matrix that compensates for non-uniformities during tomographic reconstruction

Answer

Determine how much radioactivity to inject in each patient

Answer

Measure the geometric efficiency of the collimator at each rotation angle

Answer

Verify correct table height during patient acquisition