MRI Visualization and Distribution Patterns of Foreign Modeling Agents: A Brief Pictorial Review for Clinicians

Since the ancient Egyptians, people have always been worried about their physical appearance. Nowadays, for some cultures like Latin American, physical appearance depends on the context, and the concept of beauty is to have wider hips and more prominent buttocks. One way to achieve these goals is to inject foreign modelants that include some oils to modify certain body regions. Until today, the search continues to find a modelling agent that is nonteratogenic, noncarcinogenic, and not susceptible to infection and can stay at the spot where it was injected (not migration). This review is aimed at providing a brief, comprehensive assessment of the use of modeling agents and summarizes some key imaging features of filler-related complications. The topics of this review are historical data, epidemiology, classification of dermal fillers (xenografts, hyaluronic acid derivatives, autografts, homografts, synthetic materials), adverse reactions, imaging method used in the detection of injectable fillers, MRI patterns observed in complications of injectable fillers, and histological findings of immune response, treatment, and conclusions. We present several classifications of injectable fillers based on composition, degradation, and complications. Additionally, readers will find some representative cases of the most common locations of injectable fillers demonstrating their infiltrative MRI patterns.