A novel technique that reduces image degradation caused by respiratory motion during a PET scan was developed in a recent study at the University of Eastern Finland. Positron emission tomography is a modern nuclear medicine imaging method routinely used to detect cancer and heart conditions.
PET scanning is used for cancer staging and evaluating treatment response, as well as for studying myocardial blood flow and inflammatory diseases of the heart.
Typically, a PET scan takes several minutes, which is why movement caused by the patients breathing inevitably degrades image quality.
Degraded image quality caused by respiratory motion has been reported to affect PET scanning performed to detect cancer and heart conditions in particular.
The new technique is based on bioimpedance measurement, and it allows for image reconstruction at a specific phase of the patients breathing pattern, which makes it possible to reduce image degradation caused by motion.
In the future, the newly developed technique will enable increasingly accurate image acquisition especially during PET scans performed to detect cancers of the chest and upper abdomen and inflammatory diseases of the heart.
The study, published in the journals Medical & Biological Engineering & Computing, Physiological Measurement and Physics in Medicine and Biology, found that when synchronizing images on the basis of bioimpedance, it was possible to discern smaller details. The study first used computational models and test subjects to determine an optimized bioimpedance measurement configuration for simultaneous measurement of respiratory and cardiac gating signals. The second phase of the study focused on analyzing whether bioimpedance techniques can be used to reduce respiration-related degradation of PET images.
Bioimpedance measurement offers a straightforward technique for acquiring the data needed for motion compensation. Because of enhanced image quality, PET images provide new and increasingly accurate data, potentially improving diagnosis reliability and treatment response monitoring. High-quality image data make treatment more efficient both medically and financially. Researchers believe the technique also can be integrated easily into electrocardiogram measurement, which is widely used to monitor heart function during the PET scan.