Principles of PET CT Acquisition
PET CT combines metabolic information from PET with anatomical detail from CT and protocol design addresses tracer selection uptake time patient preparation and CT acquisition parameters that affect attenuation correction and diagnostic CT quality. Patient preparation such as fasting and glucose control influences tracer distribution and image contrast and consistent timing between injection and imaging is essential for quantitative comparisons. CT protocols may be low dose for attenuation correction or diagnostic quality for lesion characterization and harmonizing CT and PET parameters supports integrated interpretation.
Quantitative Accuracy and Harmonization
Quantitative PET metrics require cross calibration of dose calibrators and scanners and harmonization across sites for multicenter studies uses phantom based validation and standardized reconstruction settings to reduce variability. Partial volume effects and motion degrade quantification and strategies such as respiratory gating and motion correction improve accuracy for small lesions. Documenting acquisition and reconstruction parameters and participating in external quality assurance programs maintain confidence in quantitative PET metrics for clinical and research use.
Dose Management and Patient Safety
PET CT involves radiation from both the radiotracer and from the CT component and dose management strategies include optimizing tracer activity based on patient size using low dose CT when appropriate and tailoring diagnostic CT parameters to clinical need. Shielding and safe handling of radiopharmaceuticals protect staff and clear communication with patients about radiation risks and benefits supports informed consent. Monitoring and reporting of administered activities and of CT dose indices support dose audits and continuous optimization.