*Review* **Influences on PET Quantification and Interpretation**

**Julian M. M. Rogasch 1,2, Frank Hofheinz 3, Lutz van Heek 4, Conrad-Amadeus Voltin 4, Ronald Boellaard 5 and Carsten Kobe 4,\***


**Abstract:** Various factors have been identified that influence quantitative accuracy and image interpretation in positron emission tomography (PET). Through the continuous introduction of new PET technology—both imaging hardware and reconstruction software—into clinical care, we now find ourselves in a transition period in which traditional and new technologies coexist. The effects on the clinical value of PET imaging and its interpretation in routine clinical practice require careful reevaluation. In this review, we provide a comprehensive summary of important factors influencing quantification and interpretation with a focus on recent developments in PET technology. Finally, we discuss the relationship between quantitative accuracy and subjective image interpretation.

**Keywords:** positron emission tomography; quantitative accuracy; contrast recovery; signal-to-noise ratio; image interpretation; image quality
