The clearance of FDG activity in normal tissues (and thus the background level) varies significantly with extended distribution time. Although most tissues have lower SUV values on 2-hour/3-hour delayed images, others may have stable or higher FDG activity with longer distribution times. This finding has to be taken into consideration when interpreting an FDG-PET study that is performed with significantly short or long distribution time, and when comparing 2 studies with different distribution times. The continuously decreased SUV value from 1 to 3 hours in some tissues, especially in the liver, indicates that longer distribution time will decrease background activity and improve imaging quality, whereas the continuously increased SUV values from 1 to 3 hours in the heart suggest that longer distribution time will improve detection of viable myocardium in a viability study.
- Background activity
- Delayed imaging
- Distribution time
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging