Background: Although the essential components of pain pathways have been identified, a thorough comprehension of the interactions necessary for creating focused treatments is still lacking. Such include more standardised methods for measuring pain in clinical and preclinical studies and more representative study populations. Objective: This review describes the essential neuroanatomy and neurophysiology of pain nociception and its relation with currently available neuroimaging methods focused on health professionals responsible for treating pain. Methods: Conduct a PubMed search of pain pathways using pain-related search terms, selecting the most relevant and updated information. Results: Current reviews of pain highlight the importance of their study in different areas from the cellular level, pain types, neuronal plasticity, ascending, descending, and integration pathways to their clinical evaluation and neuroimaging. Advanced neuroimaging techniques such as fMRI, PET, and MEG are used to better understand the neural mechanisms underlying pain processing and identify potential targets for pain therapy. Conclusions: The study of pain pathways and neuroimaging methods allows physicians to evaluate and facilitate decision-making related to the pathologies that cause chronic pain. Some identifiable issues include a better understanding of the relationship between pain and mental health, developing more effective interventions for chronic pain's psychological and emotional aspects, and better integrating data from different neuroimaging modalities for the clinical efficacy of new pain therapies.

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.