Quality control (QC) in nuclear medicine ensures that gamma camera and PET systems produce accurate, reproducible, and diagnostically reliable images. Because radionuclide imaging depends on precise photon detection and electronic processing, even minor system deviations can degrade image quality or compromise quantitative accuracy. A structured QC programme is therefore essential for maintaining spatial resolution, uniformity, and measurement reliability.

Gamma camera QC includes routine assessment of intrinsic and extrinsic uniformity, energy peaking, photopeak stability, spatial resolution, and centre-of-rotation accuracy. Uniformity testing detects non-uniform detector response, while correct energy peaking ensures accurate photon discrimination. In SPECT imaging, centre-of-rotation errors can produce characteristic ring artefacts in reconstructed images. Collimator integrity and septal penetration may also influence system performance.

PET quality control includes blank scans, detector normalisation, timing calibration, and verification of attenuation correction systems. Because PET is inherently quantitative, rigorous QC is critical to ensure reliable standardised uptake value (SUV) measurements and longitudinal comparability.

Quality control is a high-yield topic in FRCR Part 1 Physics, ABR Core, RANZCR, and FC(Rad) Diag SA examinations. Questions commonly assess interpretation of uniformity flood images, identification of reconstruction artefacts, and understanding how QC failures affect spatial resolution and quantitative accuracy.

This section containsquestions covering uniformity testing, energy window calibration, centre-of-rotation assessment, PET normalisation procedures, and routine system performance checks. The problems are designed to reinforce both theoretical understanding and practical recognition of QC-related imaging abnormalities.

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