Organ Movement Reduction in PET/CT using Dual-Gated Listmode Acquisition

Purpose: Imaging of moving organs using the PET leads to blurred images due to long acquisition times. Simultaneous cardiac and respiratory gating of list-mode PET/CT is evaluated with the aim to improve image quality and assess the organ movement. Methods: We performed a N-13 ammonia PET/CT scan with a human volunteer, using the Siemens Biograph Sensation 16 scanner with listmode acquisition. For ECG gating we used the scanner's integrated ECG device. Respiratory gating was done with the BioVet pneumatic sensor system. Results: The sorting of the list-mode data post acquisition produced the desired matrix of eight cardiac times eight respiratory images. Organ movement could be measured in the series of gated PET images. The quantitation of tracer uptake in the myocardium showed artifacts due to the CT-based attenuation correction. Conclusion: Double gating is feasible in human PET/CT scans using a list-mode-based scan protocol. The image quality can be enhanced using double gated list-mode acquisition in PET/CT. Attenuation correction protocols in PET using a single not gated fast CT introduces artifacts in moving organs.