NMTCB Instrument Operations & Quality Control 2

Question 1

Which QC test is performed daily on a gamma camera to verify the uniformity of detector response across the field of view?

Accepted Answer

Intrinsic uniformity flood

Answer

A daily flood uniformity acquisition (intrinsic or extrinsic) confirms that detector response is uniform across the entire field of view.

Question 2

On a PET scanner, what is the purpose of performing a normalization scan?

Accepted Answer

To correct for detector efficiency variations between crystal pairs

Answer

Normalization corrects for non-uniform detector efficiencies among the many crystal pairs in a PET ring so that reconstructed images have uniform sensitivity.

Question 3

A technologist notices that the center of rotation (COR) for a SPECT system is off by more than 2 pixels. What is the most likely consequence if imaging proceeds without correction?

Accepted Answer

Ring artifacts in reconstructed SPECT images

Answer

An uncorrected COR offset causes ring or 'bull's-eye' artifacts in SPECT reconstructed images, degrading image quality significantly.

Question 4

What does the energy resolution of a scintillation detector describe?

Accepted Answer

The ability to distinguish photons of slightly different energies

Answer

Energy resolution, expressed as % FWHM of the photopeak, reflects how well the detector discriminates between photons of closely spaced energies.

Question 5

Which quality control test for a well counter verifies that the system gives consistent counts for the same source activity on different days?

Accepted Answer

Reproducibility (precision) test

Answer

A reproducibility or precision test involves repeated counting of a long-lived standard source to confirm day-to-day consistency of the well counter.

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

(NMTCB) Nuclear Medicine Technology Certification Board Practice Test

NMTCB Instrument Operations & Quality Control 2