Focusing on the face, this chapter outlines the diagnostic approach to permanent synthetic fillers through magnetic resonance imaging (MRI) and high-resolution ultrasound. It explains imaging techniques and filler presentations in common facial sites like the lips, cheeks, and jawline. MRI offers deep tissue evaluation, while ultrasound allows for real-time assessment of superficial structures and dynamic evaluation. This chapter highlights specific ultrasound artifacts such as “snowstorm” and pseudo-cyst patterns, and introduces preoperative facial skin marking guided by ultrasound as a tool for surgical planning. It also discusses challenges in filler identification due to mixed substances and incomplete patient history.