What is SUV and what affects it? SUV (Standardised Uptake Value) is a semi-quantitative measure used in PET imaging to estimate tracer uptake within a region, normalised for administered activity and patient size. It is most commonly used in FDG…
What determines quantitative accuracy in PET? Quantitative accuracy in PET refers to how closely measured activity concentrations reflect the true tracer concentration within tissues. It is determined by correct calibration, accurate attenuation and scatter correction, count statistics, spatial resolution effects,…
What is recovery coefficient in PET? The recovery coefficient (RC) in PET is a measure of how accurately the measured activity concentration in a structure reflects its true activity concentration. It quantifies the impact of partial volume effects on small…
What determines spatial resolution in SPECT and PET? Spatial resolution in SPECT and PET is determined by different dominant physical factors. In SPECT, spatial resolution is primarily limited by collimator geometry and source-to-detector distance. In PET, spatial resolution is limited…
What is the partial volume effect in SPECT and PET? The partial volume effect is the underestimation of true tracer uptake in small structures due to limited spatial resolution. When a structure is smaller than approximately two to three times…
What determines contrast resolution in SPECT and PET? Contrast resolution in SPECT and PET is determined primarily by count statistics, noise, scatter, attenuation effects, and reconstruction parameters. It reflects the ability to detect differences in tracer uptake between adjacent regions.…
What is spatial resolution versus contrast resolution in radionuclide imaging? Spatial resolution refers to the ability of an imaging system to distinguish two closely spaced structures as separate. It describes how sharply edges and small objects are represented. Contrast resolution…
What determines image quality in radionuclide imaging? Image quality in radionuclide imaging is determined by a combination of count statistics, spatial resolution, contrast resolution, and physical correction modelling (including attenuation and scatter correction). Unlike CT or MRI, image quality in…
What is PET reconstruction? PET reconstruction is the mathematical process of converting millions of detected coincidence events into cross-sectional images representing the three-dimensional distribution of radiotracer activity. Each coincidence event defines a line of response along which the annihilation occurred.…
What is attenuation correction in PET? Attenuation correction in PET compensates for the loss of annihilation photons as they pass through the body before reaching the detectors. Without correction, deeper structures appear falsely less active because fewer photons are detected.…
