In this issue of PET Clinics, guest editors Drs. Nicolas A. Karakatsanis and Abass Alavi bring their considerable expertise to the topic of PET Image Quantification: Novel Methods, Challenges, and Opportunities. Top experts present an overview of the latest developments and challenges in quantitative clinical PET data correction methods and how the latest advancements in multi-parametric imaging, dual-tracer protocols, artificial intelligence, and total-body scanners are paving the way to overcome current challenges and open new opportunities for improved quantitative accuracy. Contains 16 relevant, practice-oriented topics including quantitative PET imaging in clinic: basic data correction methods and modern challenges; whole-body dynamic and multi-parametric PET imaging: towards enhanced diagnostic, treatment response and theranostics quantification in the clinic; the importance of PET quantification for treatment response monitoring; the role of PET image quantification in radiation therapy; and more Provides in-depth clinical reviews on PET image quantification, offering actionable insights for clinical practice Presents the latest information on this timely, focused topic under the leadership of experienced editors in the field. Authors synthesize and distill the latest research and practice guidelines to create clinically significant, topic-based reviews