Bioimpedance-based respiratory gating method for oncologic positron emission tomography (PET) imaging with first clinical results

Respiratory motion may cause significant image artefacts in positron emission tomography/computed tomography (PET/CT) imaging. This study introduces a new bioimpedance-based gating method for minimizing respiratory artefacts. The method was studied in 12 oncologic patients by evaluating the following three parameters: maximum metabolic activity of radiopharmaceutical accumulations, the size of these targets as well as their target-to-background ratio. The bioimpedance-gated images were compared with nongated images and images that were gated with a reference method, chest wall motion monitoring by infrared camera. The bioimpedance method showed clear improvement as increased metabolic activity and decreased target volume compared to non-gated images and produced consistent results with the reference method. Thus, the method may have great potential in the future of respiratory gating in nuclear medicine imaging.