Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) is an established tool in clinical molecular imaging for evaluating metabolic activity. Advanced PET systems enable high-resolution three-dimensional analysis of FDG distribution, offering insightful information for lesion characterization. Furthermore, dynamic whole-body imaging facilitates assessment of temporal FDG uptake following its administration. This development introduces the concept of four-dimensional (4D) FDG PET/CT, enhancing the precision of lesion characterization. A critical advantage of applying 4D FDG PET/CT is the ability to distinguish pathological from physiological FDG uptake by analyzing motion-related uptake. Correcting motion and integrating serial imaging data enable accurate interpretation. Additionally, FDG uptake quantification is possible using Patlak analysis. This review discusses innovative clinical applications and quantitative techniques for analyzing FDG distribution through 4D FDG PET/CT.