attenuation correction
Image processing technique compensating for photon absorption in PET imaging.
Full Definition
Attenuation correction is a fundamental image processing step in PET imaging that compensates for the absorption and scattering of annihilation photons as they traverse body tissues. Different tissues absorb photons at varying rates, with bone and contrast material causing more attenuation than soft tissues. Without correction, deeper structures appear artifactually less active than superficial ones. Modern PET/CT scanners use the CT transmission data to create an attenuation map, mathematically correcting for tissue-specific photon absorption. Proper attenuation correction is essential for accurate SUV calculations and quantitative PET analysis, and artifacts from incorrect attenuation correction can mimic or mask pathology.
Usage
Usage note: Critical for quantitative PET analysis - artifacts can significantly affect SUV measurements.
In Context
- "Metallic implants caused attenuation correction artifacts in the pelvic region." — PET/CT interpretation
- "Both attenuation corrected and non-corrected images should be reviewed for optimal interpretation." — nuclear medicine protocol