Ultra-low-dose CT for positron emission tomography: Feasibility, limitations, and quantitative impact

The thesis examines how much radiation from the CT component of PET/CT examinations can be curtailed without compromising PET reliability. Using long-axial-field-of-view scanners, several ultra-low-dose CT techniques were tested in phantoms and patients. In one clinical study, cutting the CT radiation dose by around 97% produced differences in primary PET measurements that generally remained under 3%.

The work also assessed automated organ segmentation at very low doses alongside artificial intelligence enhancement. AI improved image quality but could not fully replace standard CT when fine anatomical detail was required. Photon-counting CT was additionally identified as a promising low-dose avenue. Overall, ultra-low-dose CT can sharply decrease radiation while retaining dependable PET data, though optimal doses depend on patient needs and scan purposes.